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SUMMARY TECHNICAL REPORT 
OF THE 

NATIONAL DEFENSE RESEARCH COMMITTEE 


This document contains information affecting the national defense of the 
United States within the meaning of the Espionage Act, 50 U. S. C., 
31 and 32, as amended. Its transmission or the revelation of its contents 
in any manner to an unauthorized person is prohibited by law. 

This volume is classified CONFIDENTIAL in accordance with security 
regulations of the War and Navy Departments because certain chapters 
contain material which was CONFIDENTIAL at the date of printing. 
Other chapters may have had a lower classification or none. The reader 
is advised to consult the War and Navy agencies listed on the reverse of 
this page for the current classification of any material. 


CONFIDENTIAL 


Manuscript and illustrations for this volume were prepared 
for publication by the Summary Reports Group of the Colum¬ 
bia University Division of War Research under contract 
OEMsr-1131 with the Office of Scientific Research and De¬ 
velopment. This volume was printed and bound by the 
Columbia University Press. 

Distribution of the Summary Technical Report of NDRC has 
been made by the War and Navy Departments. Inquiries 
concerning the availability and distribution of the Summary 
Technical Report volumes and microfilmed and other refer¬ 
ence material should be addressed to the War Department 
Library, Room 1A-522, The Pentagon, Washington 25, 
D.C., or to the Office of Naval Research, Navy Department, 
Attention: Reports and Documents Section, Washington 25, 
D. C. 


Copy No. 

239 

This volume, like the seventy others of the Summary Techni¬ 
cal Report of NDRC, has been written, edited, and printed 
under great pressure. Inevitably there are errors which 
have slipped past Division readers and proofreaders. There 
may be errors of fact not known at time of printing. The 
author has not been able to follow through his writing to 
the final page proof. 

Please report errors to: 

JOINT RESEARCH AND DEVELOPMENT BOARD 
PROGRAMS DIVISION (STR ERRATA) 

WASHINGTON 25, D. C. 

A master errata sheet will be compiled from these reports 
and sent to recipients of the volume. Your help will make 
this book more useful to other readers and will be of great 
value in preparing any revisions. 



SUMMARY TECHNICAL REPORT OF DIVISION 11, NDRC 

VOLUME 2 


MISCELLANEOUS CHEMICAL 
ENGINEERING PROBLEMS 



VANNEVAR BUSH, DIRECTOR 

NATIONAL DEFENSE RESEARCH COMMITTEE 
JAMES B. CONANT, CHAIRMAN 

DIVISION 11 
H. M. CHADWELL, CHIEF 


WASHINGTON, D. C., 1946 




By 


^NATIONAL DEFENSE RESEARCH COMMITTEE 

stf ® 10 James B. Conant, Chairman 

Richard C. Tolman, Ttce Chairman 


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0 


\ 


. ,<r \ ’Roger Adams 


D^ens® 
a ***® 1 


Army Representative 1 
Navy Representative 2 
Karl T. Compton Commissioner of Patents 3 

Irvin Stewart, Executive Secretary 


AErank B. Jewett 

O? ^ 


1 Army representatives in order of service: 


Maj. Gen. G. V. Strong 
Maj. Gen. R. C. Moore 
Maj. Gen. C. C. Williams 
Brig. Gen. W. A. Wood, Jr. 


Col. L. A. Denson 
Col. P. R. Faymonville 
Brig. Gen. E. A. Regnier 
Col. M. M. Irvine 


Col. E. A. Routheau 


2 Navy representatives in order of service: 

Rear Adm. H. G. Bowen Rear Adm. J. A. Furer 

Capt. Lybrand P. Smith Rear Adm. A. H. Van Keuren 

Commodore H. A. Schade 
3 Commissioners of Patents in order of service: 
Conway P. Coe Casper W. Ooms 


NOTES ON THE ORGANIZATION OF NDRC 


The duties of the National Defense Research Committee 
were (1) to recommend to the Director of OSRD suitable 
projects and research programs on the instrumentalities 
of warfare, together with contract facilities for carrying 
out these projects and programs, and (2) to administer 
the technical and scientific work of the contracts. More 
specifically, NDRC functioned by initiating research 
projects on requests from the Army or the Navy, or on 
requests from an allied government transmitted through 
the Liaison Office of OSRD, or on its own considered ini¬ 
tiative as a result of the experience of its members. Pro¬ 
posals prepared by the Division, Panel, or Committee for 
research contracts for performance of the work involved 
in such projects were first reviewed by NDRC, and if 
approved, recommended to the Director of OSRD. Upon 
approval of a proposal by the Director, a contract per¬ 
mitting maximum flexibility of scientific effort was ar¬ 
ranged. The business aspects of the contract, including 
such matters as materials, clearances, vouchers, patents, 
priorities, legal matters, and administration of patent 
matters were handled by the Executive Secretary of 
OSRD. 

Originally NDRC administered its work through five 
divisions, each headed by one of the NDRC members. 
These were: 

Division A — Armor and Ordnance 
Division B — Bombs, Fuels, Gases, & Chemical Prob¬ 
lems 

Division C — Communication and Transportation 
Division D — Detection, Controls, and Instruments 
Division E — Patents and Inventions 


In a reorganization in the fall of 1942, twenty-three 
administrative divisions, panels, or committees were cre¬ 
ated, each with a chief selected on the basis of his out¬ 
standing work in the particular field. The NDRC mem¬ 
bers then became a reviewing and advisory group to the 
Director of OSRD. The final organization was as follows: 


Division 1 — Ballistic Research 

Division 2 — Effects of Impact and Explosion 

Division 3 — Rocket Ordnance 

Division 4 — Ordnance Accessories 

Division 5 — New Missiles 

Division 6 — Sub-Surface Warfare 

Division 7 — Fire Control 

Division 8 — Explosives 

Division 9 — Chemistry 

Division 10 — Absorbents and Aerosols 

Division 11 — Chemical Engineering 

Division 12 — Transportation 

Division 13 — Electrical Communication 

Division 14 — Radar 

Division 15 — Radio Coordination 

Division 16 — Optics and Camouflage 

Division 17 — Physics 

Division 18 — War Metallurgy 

Division 19 — Miscellaneous 

Applied Mathematics Panel 

Applied Psychology Panel 

Committee on Propagation 

Tropical Deterioration Administrative Committee 



2015 


490935 


















NDRC FOREWORD 


A S events of the years preceding 1940 re¬ 
pealed more and more clearly the serious¬ 
ness of the world situation, many scientists in 
this country came to realize the need of or¬ 
ganizing scientific research for service in a 
national emergency. Recommendations which 
they made to the White House were given care¬ 
ful and sympathetic attention, and as a result 
the National Defense Research Committee 
[NDRC] was formed by Executive Order of the 
President in the summer of 1940. The members 
of NDRC, appointed by the President, were 
instructed to supplement the work of the Army 
and the Navy in the development of the instru¬ 
mentalities of war. A year later, upon the 
establishment of the Office of Scientific Re¬ 
search and Development [OSRD], NDRC be¬ 
came one of its units. 

The Summary Technical Report of NDRC is 
a conscientious effort on the part of NDRC to 
summarize and evaluate its work and to pre¬ 
sent it in a useful and permanent form. It 
comprises some seventy volumes broken into 
groups corresponding to the NDRC Divisions, 
Panels, and Committees. 

The Summary Technical Report of each Di¬ 
vision, Panel, or Committee is an integral sur¬ 
vey of the work of that group. The first volume 
of each group’s report contains a summary of 
the report, stating the problems presented and 
the philosophy of attacking them, and sum¬ 
marizing the results of the research, develop¬ 
ment, and training activities undertaken. Some 
volumes may be “state of the art” treatises 
covering subjects to which various research 
groups have contributed information. Others 
may contain descriptions of devices developed 
in the laboratories. A master index of all these 
divisional, panel, and committee reports which 
together constitute the Summary Technical 
Report of NDRC is contained in a separate vol¬ 
ume, which also includes the index of a micro¬ 
film record of pertinent technical laboratory 
reports and reference material. 

Some of the NDRC-sponsored researches 
which had been declassified by the end of 1945 
were of sufficient popular interest that it was 
found desirable to report them in the form of 
monographs, such as the series on radar by 
Division 14 and the monograph on sampling 
inspection by the Applied Mathematics Panel. 
Since the material treated in them is not dupli¬ 
cated in the Summary Technical Report of 
NDRC, the monographs are an important part 


of the story of these aspects of NDRC research. 

In contrast to the information on radar, 
which is of widespread interest and much of 
which is released to the public, the research on 
subsurface warfare is largely classified and is 
of general interest to a more restricted group. 
As a consequence, the report of Division 6 is 
found almost entirely in its Summary Tech¬ 
nical Report, which runs to 23 volumes. The 
extent of the work of a division cannot there¬ 
fore be judged solely by the number of volumes 
devoted to it in the Summary Technical Re¬ 
port of NDRC: account must be taken of the 
monographs and available reports published 
elsewhere. 

One can claim on behalf of Division 11 that 
the results of its work contributed directly and 
dramatically to the successful prosecution and 
triumphant termination of World War II. It 
was Division 11, under the leadership first of 
R. P. Russell, then E. P. Stevenson, and later 
H. M. Chadwell, which developed the incen¬ 
diary bombs with which Japan’s industrial 
plants were reduced to ashes. Filled with jellied 
gasoline, the AN-M69 incendiary was credited 
with the highest efficiency of any bomb against 
Japanese factories and dwellings. More than 
40,000 tons of AN-M69 bombs were dropped on 
Japanese cities. 

Division 11 likewise applied the use of thick¬ 
ened fuels to portable and mechanized flame 
throwers, which were employed with great 
success against the enemy in the Pacific. Other 
sections of the Division did important work in 
developing improved techniques for the produc¬ 
tion of oxygen for military uses, and in solving 
numerous other problems in the field of chemi¬ 
cal engineering, one of the most valuable con¬ 
tributions being the development of new hy¬ 
draulic fluids. 

This Summary Technical Report of Division 
11, prepared under the direction of the Divi¬ 
sion Chief and authorized by him for publica¬ 
tion, describes the activities ot the Division 
and its contractors. It stands as a testimonial 
to the imagination and resourcefulness of 
American scientists and industrial engineers 
and as a record of wartime accomplishment 
worthy of grateful recognition. 

Vannevar Bush, Director 

Office of Scientific Research and Development 

J. B. CONANT, Chairman 
National Defense Research Committee 




v 

























































FOREWORD 


F or administrative purposes and because of 
the diverse nature of the problems studied 
by Division 11 (Chemical Engineering) of 
NDRC, three independent sections were cre¬ 
ated: Section 11.1 (Oxygen Problems), Section 
11.2 (Miscellaneous Chemical Engineering 
Problems), and Section 11.3 (Fire Warfare). 
The work of each of the three sections is pre¬ 
sented in an individual volume of the Summary 
Technical Report of NDRC. 

The work of Section 11.2, reported in this 
volume, was unusual in that it involved re¬ 
search and development projects of such ex¬ 
treme diversification. As the activities of 
NDRC increased, various research programs 
took shape and were defined by the creation of 
divisions and sections. Section 11.2 remained 
as the residue of this development of the 
NDRC organization, being assigned quite mis¬ 
cellaneous chemical and chemical engineering 
projects not logically falling in the field of 
effort of the other sections of Division 11, or 
of Divisions 8, 9, and 10. This may serve to 
explain the unusual variety of projects indi¬ 
cated by the list of chapter headings. 

The work of Section 11.2 was carried out 
under the direction of Mr. R. P. Russell (Janu¬ 
ary and February 1943), Mr. E. P. Stevenson 
(March 1943 to February 1945), and Dr. H. 
M. Chadwell (March 1945 to termination) as 
Chiefs of Division 11 for the periods indicated, 
and of Dr. T. K. Sherwood (January 1943 to 
termination) as Chief of Section 11.2. Assisting 
them were Mr. R. C. Wilcox, Mr. Abbott 
Byfield, and Mr. F. E. Vinal as Technical Aides 
of Section 11.2. 

In 1942 the section was presented with 
several problems by the Office of the Quarter¬ 
master General, and certain contracts were 
initiated with research and development agen¬ 
cies. Mr. Stanley Lovell joined the section as a 
Technical Aide at that time, devoting his 
efforts entirely to the OQMG projects. In 1943 
this work was transferred to a Committee on 
Quartermaster Problems of the National Re¬ 
search Council, with L. W. Bass as chairman, 
where it was handled by sub-contracts under a 
prime contract between OSRD and NRC. This 
contract was supervised directly by the office of 
the chairman of NDRC. It was returned to 
Section 11.2 in the late spring of 1944, however, 
and in December 1944, was transferred to the 


OQMG. Although started in Section 11.2, the 
work accomplished on the various projects for 
the Quartermaster General was done almost 
entirely under the direction of the NRC Com¬ 
mittee on Quartermaster Problems, consisting 
of W. M. Clark, K. H. Condit, S. D. Kirk¬ 
patrick, N. A. Shepard, Raymond Stevens, and 
F. W. Willard, with L. W. Bass as chairman. 

The Summary Technical Report of this sec¬ 
tion is divided in two parts: Part I, on general 
projects, prepared by T. K. Sherwood and R. 
C. Wilcox, with the assistance of several of the 
contractors; and Part II, covering the Quarter¬ 
master problems, prepared by W. G. Parks, 
Technical Aide to the NRC Committee on 
Quartermaster Problems. The coordination 
within the section was supervised first by R. 
C. Wilcox and later by D. Churchill, Jr. To all 
of these men the Division Chief wishes to ex¬ 
press his sincere thanks. 

In many instances industrial and university 
contractors undertook research of a definitely 
hazardous character without hesitation or com¬ 
plaint. While engaged in tests of an anti¬ 
submarine flare, Charles R. Hoover lost his 
life in a blimp accident in 1942. The courage 
and devotion of such men, though seldom pub¬ 
licized, were necessary parts of the successful 
whole war effort. 

Because of the varied nature of the projects, 
it was necessary to obtain the advice and guid¬ 
ance of specialists in several fields, and ac¬ 
knowledgment is due a great many people in 
this regard. Special thanks are due G. H. B. 
Davis, C. K. Drinker, W. K. Lewis, A. J. Weith, 
and M. R. Fenske. The successful administra¬ 
tion of the section’s affairs was largely in the 
hands of R. C. Wilcox, Technical Aide, whose 
loyalty and good judgment made possible much 
of what was accomplished. 

Acknowledgment is made of the valuable as¬ 
sistance rendered by the Services and by the 
liaison officers assigned by them to the various 
projects. 

The Division Chief also wishes to acknowl¬ 
edge with thanks the valuable help and guid¬ 
ance in broad phases of the program and policy 
of Dr. Roger Adams, Member of NDRC. 

H. M. Chadwell 
Chief, Division 11 
Thomas K. Sherwood 
Chief, Section 11.2 



vii 




CONTENTS 


PART 1 

GENERAL PROJECTS 
By T. K. Sherwood and F. C. Wilcox 

CHAPTER PAGE 

1 Hydraulic Fluids. 1 

2 Dust Removal from Aircraft Engine Air 

Supply. 14 

3 Protection of Aircraft Fuel Tanks Against 

Explosion. 16 

4 Pyrotechnics—Flares; Photoflash Bombs 20 

5 Improved Inflation of Life Rafts at Low 

Temperatures. 32 

6 Advanced Position Identification ... 37 

7 Chemicals for Generation of Hydrogen . 41 

8 Plane Crash Dye Marker. 47 

9 Development of Oxygen Masks ... 49 

10 Levinstein-H. 53 

11 Exterior Ballistics of Liquid-Filled Shells 65 

12 Hydrogen Generator for Pressurizing 

Portable Flame Throwers .... 72 

13 Instantaneous Respiration Rates ... 77 

14 Sabotage of Gasoline Engines .... 84 

15 Production of Potable Water from Sea 

Water. 88 

16 Underwater Coatings. 92 

17 Corrosion Resistant Linings and Coatings 110 

18 Cleaning of Gasoline Containers for Use 

in Transporting Drinking Water . . . 116 

19 Production of Magnesium Fluoride . . 117 

20 Substitute for Cork in Ordnance Plugs . 119 

21 Improvement of Submarine Storage Bat¬ 
teries .120 

22 Removal of Oil from Harbor Waters . . 121 











CONTENTS 


CHAPTER PAGE 

23 Production of Nitric Acid from Urine . 122 

24 Suppression of Dust Around Artillery Em¬ 
placements .127 

25 Manufacture of Hydrogen Peroxide . . 132 

PART 11 

QUARTERMASTER PROBLEMS 
By George W. Parks 

26 Improvement of Shoes.138 

27 Improvement of Leather.141 

28 Deleading of Gasoline.143 

29 Evaluation Procedures for Water-Repel- 

lency Treatments.145 

30 Insects and Other Animals of Interest. . 148 

31 Troop Feeding Programs.151 

32 Western Hemisphere Bamboo as a Substi¬ 
tute for Oriental Bamboo.153 

33 Solid Fuel for Heating Combat Rations . 156 

34 Literature Search on Carbonaceous Fuels 

for Heating Combat Rations .... 158 

35 Flameproofing of Textiles for Army 

Clothing.160 

36 Organic Coatings.164 

37 Coated Fabrics and Thin Films . . . 167 

38 Wear Resistance of Apparel Textiles . . 173 

39 Shrinkproofing of Wool Knitted Items and 

Fabrics.176 

40 Packaging with Plastics.178 

41 Storage of Chlorinated Lime .... 182 

Bibliography.187 

OSRD Appointees.198 

Contract Numbers.200 

Service Project Numbers.206 

Index.209 
















Chapter 1 

HYDRAULIC FLUIDS 


i- 1 SUMMARY 

T he various military uses of hydraulic 
fluids and recoil oils are described, and the 
desirable and necessary characteristics of these 
fluids are summarized. Fluids available in 1941 
proved to have many deficiencies, in many cases 
of such a serious nature as to make the gun 
turret or other mechanism inoperative at low 
temperatures. It was found that suitable fluids, 
having excellent properties at both low and 
high temperatures, could be prepared by incor¬ 
porating high-polymeric additives such as cer¬ 
tain acrylic esters in properly prepared hydro¬ 
carbon base stocks. In addition to the viscosity- 
temperature slope, many other factors such as 
shear stability, tackiness, and oxidation resis¬ 
tance proved to be important. 

Specifications were issued for aircraft hy¬ 
draulic fluids, Army recoil oils, and Navy ship¬ 
board hydraulic fluids, and large quantities of 
each were procured. As compared with the 
1941 specification, the new aircraft fluid had 
a greater viscosity above 130 F and a viscosity 
of 500 or less in place of the previous 7,000 
centistokes at —40 F. This reduction in low- 
temperature viscosity was sufficient to mean 
the difference between the equipment working 
and not working in many cases. A satisfactory 
noninflammable hydraulic fluid for general use 
was not developed. 


12 INTRODUCTION 

Hydraulic fluids are used in Army, Navy, 
and Air Force ordnance equipment for the 
transmission as well as the dissipation of en¬ 
ergy over wide temperature ranges. A simple 
illustration of the application of hydraulic 
power is hydraulic brakes commonly employed 
on automobiles. In their operation a fluid trans¬ 
mits the power to the brake through a small 
tube. This is simpler and more effective than 
a relatively complex system of mechanical 


links and levers to accomplish the same result. 

Hydraulically operated devices on aircraft 
are of many types. They include actuating 
equipment for landing gears, wing flaps, 
brakes, and control and steering equipment 
pertaining to the automatic pilot. In certain 
instances there are time sequences involved, 
such as in raising and lowering undercarriages 
and their doors or housings. On flying boats 
there are hydraulically operated retractable 
floats. Bomb doors are operated against vary¬ 
ing aerodynamic loads. In some of the large 
planes, there is hydraulic steering on the 
ground through the nose wheel. Hydraulic 
fluids are necessary in shock absorbers. In ad¬ 
dition to the foregoing, there are important 
applications in gun turrets and fire controls. 
In some of the very large airplanes it is nec¬ 
essary to apply hydraulic operation to the sur¬ 
face controls, as the forces involved in flight 
are so large that manual operation is no longer 
possible. Some variable-pitch propellers are 
also hydraulically operated. Combinations of 
hydraulic and electric devices are frequently 
employed. 

Navy ordnance equipment employs hydraulic 
power to train and elevate the various guns 
ranging from the 40-mm to the large 16-in. 
size. Projectile and ammunition hoists are also 
hydraulically operated on shipboard. Ships 
are steered by the application of hydraulic 
power. On aircraft carriers hydraulic fluids 
are used in arresting gears and catapults, in 
addition to all the other uses normally em¬ 
ployed on combat vessels. 

In Army ordnance equipment, hydraulic 
fluids are used in recoil mechanisms of field 
guns, howitzers, and antiaircraft guns. In these 
cases part of the energy of recoil is absorbed by 
the oil and converted into heat, as the oil is 
forced through various throttling devices and 
orifices. Hydraulic equipment is also used to 
train guns and carry out other fire-control op¬ 
erations in tanks and armored equipment. 

In addition to the foregoing, there are cer- 


1 


2 


HYDRAULIC FLUIDS 


tain other highly specialized uses for specific 
fluids. Although the quantity involved here is 
not as large, the application is equally impor¬ 
tant. Compass oils are one example. Special 
damping fluids for fire-control equipment is an¬ 
other illustration of the use of specific liquids 
for highly specialized purposes in warfare. 


13 CHARACTERISTICS OF DESIRABLE 
HYDRAULIC FLUIDS 

The hydraulic fluids used in ordnance equip¬ 
ment must have sufficient viscosity and lubri¬ 
cation properties to provide adequate protec¬ 
tion to all the moving parts at the highest tem¬ 
peratures encountered during use. These may 
exceed 250 F. Sufficient viscosity is also needed 
to prevent internal and external leakage. Many 
hydraulic devices will not function properly if 
there is excessive leakage past valves, pistons, 
and other close-fitting and moving parts within 
the hydraulic system. Leakage past glands, 
gaskets, and other sealing devices into the 
surroundings is obviously objectionable. At the 
same time such fluids must possess a relatively 
high fluidity at the lowest operating tempera¬ 
tures encountered in the different hydraulic 
systems, for it is obvious that a sluggish or im¬ 
movable fluid can readily cause malfunctioning 
of hydraulic equipment. Hydraulic fluids 
should be nontoxic; they should not corrode 
the various metals in the hydraulic system and 
should not be harmful to the gaskets and seal¬ 
ing devices which are usually made of syn¬ 
thetic rubber. They must not oxidize or change 
chemically so as to impair their properties and 
usefulness. They should not evaporate read¬ 
ily, and their stability and service life should 
be long. In most instances it is also desirable 
that they offer some protection against rusting. 

The mechanical design of the various hy¬ 
draulic mechanisms and recoil devices in ex¬ 
istence and in production in the early part of 
World War II was such as to require the 
use of a new hydraulic fluid if this equipment 
was to work over the wide temperature ranges 
anticipated, and if it was to remain in opera¬ 
tion over long periods of time under the most 
adverse climatic and service conditions. One 


of the important requirements was to improve 
the viscosity-temperature properties of the 
fluid. This would enable much of the equip¬ 
ment to be utilized over temperature ranges 
not otherwise possible without making changes 
in its design or in its manufacture. It was 
obviously a simple procedure to remove the old 
oil and replace it with a new variety, if this 
would accomplish the desired results. In a 
large number of instances, this simple expe¬ 
dient of using an improved hydraulic oil has 
extended the climatic and service operability 
of ordnance equipment well beyond the re¬ 
quested ranges. 

An ideal hydraulic fluid has a relatively 
large number of specific properties, and each 
must be held within definite limits. Since it 
was very doubtful that a single pure substance 
could possess all of these properties (which 
may be 20 or more), it was evident that this 
ideal fluid would have to be a carefully pre¬ 
pared mixture of various ingredients. How¬ 
ever, the problem of retaining each property 
somewhere near its optimum value without 
jeopardizing any of the other properties, or 
the availability of the fluid, was a sizable task. 
Hundreds of combinations of materials were 
tested before the proper formula was found. 


14 AIRCRAFT FLUIDS 

A fluid with a much flatter viscosity-tem¬ 
perature curve than was available in the two 
specification fluids used at the start of World 
War II was desired for aircraft. Specification 
3580 related to a hydrocarbon base fluid, while 
specification 3586 covered a castor oil base 
fluid. It was also desired to have only one type 
and grade of aircraft hydraulic fluid to elimi¬ 
nate confusion, and to simplify problems of 
manufacture and supply. In the early part of 
the war it was found that 3580 or 3586 fluids 
did not permit certain vitally important hy¬ 
draulic devices on aircraft, such as flight equip¬ 
ment, turrets, and other fire-control devices to 
operate satisfactorily. To obtain relief, various 
expedients were used, such as adding kerosene 
to the hydrocarbon base hydraulic fluid then 
in use. In addition, some of the newer develop- 




USE OF POLYMERIC ADDITIVES 


3 


ments in hydraulic mechanisms employed pres¬ 
sures up to 3,000 psi. A fluid was needed suit¬ 
able for these pressures as well as for higher 
operating temperatures, which were frequently 
encountered when compact hydraulic units 
were in operation for long periods of time. 
There were also problems of leakage. Many of 
these could be solved if the fluid had less effect 
on the various rubber parts which were used 
in hydraulic systems for sealing purposes, and 
if it would not thin out too much at the higher 
temperatures. It was apparent that the new 
hydraulic oil should be fluid at —65 F, and that 
its viscosity should be as uniform as possible 
throughout the range from about — 65 to 250 F. 


15 RECOIL OILS 

Improved Army ordnance fluids were de¬ 
sired in order to make the various recoil mech¬ 
anisms on the different guns operative with a 
single fluid at temperatures ranging from about 
—30 to about 200 F. There were several grades 
of recoil oil in use at the start of the war, and 
it was desired to eliminate these and consolidate 
them into one grade. It was found that some 
of the recoil mechanisms would not operate 
satisfactorily at high temperatures if they had 
been provided originally with a light oil, which 
would enable their low-temperature perform¬ 
ance to be satisfactory. If a fluid could be 
provided that would permit all the equipment 
to be operated at all temperatures to be en¬ 
countered in the field, it would simplify main¬ 
tenance as well as supply. Since hydraulic 
fluids are used to train and elevate guns, it 
was also desired to use this recoil oil as the 
hydraulic fluid for these operations. 


16 HYDRAULIC FLUIDS FOR 

SHIPBOARD USE 

Some of the problems relating to Army ord¬ 
nance equipment were also prevalent in Navy 
equipment. For example, in connection with 
Navy antiaircraft guns, it was found that the 
existing fluid would not provide satisfactory 
control in elevation and in train at tempera¬ 


tures below about +30 F. There was no time 
to redesign these complex units. It was im¬ 
perative to have a fluid with a flatter viscosity- 
temperature curve so that this vital equipment 
could operate at temperatures from subzero 
to the highest to be encountered, which might 
extend to 250 or 300 F. Difficulties were 
also arising because some of the fluids then 
in use did not have an adequate service life. 
Degradation of some of these fluids occurred 
in service. This was a very serious matter be¬ 
cause of the complexity and relative inaccessi¬ 
bility of hydraulic equipment on shipboard. 
Protection against rusting was desired. In ad¬ 
dition, improvements were also needed in the 
lubricating properties and in the overall sta¬ 
bility and performance characteristics. While 
it was clear that the new hydraulic fluid should 
possess a flatter viscosity-temperature curve, 
it was also evident that this property alone 
could not solve all the difficulties. Conse¬ 
quently, a complete and thorough analysis was 
made of all requirements of Navy hydraulic 
fluids so that the necessary research and de¬ 
velopment work could proceed in a logical man¬ 
ner toward the attainment of improved com¬ 
position and formula that would eliminate the 
troubles. 


17 USE OF POLYMERIC ADDITIVES 

One way to produce liquids having lower vis¬ 
cosity-temperature coefficients was to employ 
certain soluble linear-type polymers. In view 
of the practicability of this plan, it was given 
detailed study. In order to meet all other re¬ 
quirements it was necessary to investigate a 
very large number of chemical compounds and 
petroleum products. Even after investigating 
many hundred fluids, it was found that only 
3 or 4 per cent of these showed promise of 
meeting most of the requirements. Consider¬ 
ably more work was required to find the best 
formulas using materials that could be con¬ 
verted promptly into hydraulic fluids. Nearly 
200 different polymers and over 20 different 
petroleum base stocks were investigated. In 
addition, all new developments by the chemical 
industry, including silicone oils, chlorinated 





4 


HYDRAULIC FLUIDS 


hydrocarbons, and the new fluids developed by 
the Carbide and Carbon Chemicals Company, 
were studied from the standpoint of fulfilling 
all specific Service needs, as well as meeting 
the requirements for production and availabil¬ 
ity. However, each of these new fluids was 
found to be deficient in some important prop¬ 
erty. 

As the work progressed, it became clear that 
the best overall combination of properties could 
be obtained by using selected petroleum frac¬ 
tions along with carefully prepared oil-soluble 
polymers and other additives. This type of 
fluid had the additional advantage that it could 
be produced fairly readily with the minimum 
of new materials, chemicals, and plant facili¬ 
ties. This was very important at the period 
in World War II when manpower and supplies 
were extremely critical. Two linear-type poly¬ 
meric compounds were found to be suitable 
for use in certain carefully selected petroleum 
fractions. One is polybutene, which is a spe¬ 
cial variety of polymerized isobutylene. The 
other is an acrylic acid ester polymer known 
as Acryloid. It was necessary to study a wide 
molecular weight range of these polymers to 
find the optimum molecular sizes for hydraulic 
fluids. In the case of the Acryloids, it was also 
essential to study the chemical make-up of 
these polymers in addition to their size, for 
this markedly affected the low-temperature 
properties of the fluids as well as their vis¬ 
cosity-temperature characteristics. 

Acrylic acid ester polymers compounded 
from alcohols containing more than about 12 
carbon atoms formed thixotropic gels at tem¬ 
peratures below —30 F. Polymers made from 
alcohols having less than about 4 carbon atoms, 
or aryl substituted alcohols, possessed limited 
solubility in conventional hydrocarbon base 
stocks. Acryloid polymers formulated from the 
intervening alcohols (about 4 to 12 carbon 
atoms) were generally found to be suitable for 
use in petroleum base stocks. Studies were 
then carried out to determine which molecular 
types were the most suitable for improving 
the viscosity-temperature characteristics of hy¬ 
draulic fluids. The use of certain alcohols was 
also limited by their commercial availability. 
The 4-, 8-, 10-, and 12-carbon atom alcohols 


varied in their availability. During the early 
portion of the work the 8-carbon atom alcohol 
was more available than the others. When this 
alcohol became difficult to obtain it was found 
possible to prepare polymers by using the other 
alcohols. Mixtures of the 8- and 10-carbon 
atom alcohols, and the 8-, 10-, and 12-carbon 
atom alcohols were found to be suitable for 
preparing polymers when the supply of any 
one alcohol was limited. Little basic difference 
was found between polymers compounded from 
one alcohol and those compounded from alco¬ 
hol mixtures within the 8- to 12-carbon atom 
range. Acrylic acid ester polymers, prepared 
from mixtures of the 4- and 12-carbon atom 
alcohols, were also found to be suitable for 
improving the viscosity-temperature character¬ 
istics of a petroleum base stock. 

The molecular weight of the polymers was 
found to be of utmost importance. For an 
Acryloid polymer prepared from a given alco¬ 
hol or alcohol mixture, the molecular weight 
was found to have an important effect on the 
viscosity-temperature properties of any base 
stock in which it was employed. Because of the 
difficulty of measuring the actual molecular 
weights of the polymers, a relative molecular 
weight scale was devised which was found to 
be applicable to the range of polymer molecu¬ 
lar weights employed in the formulation of 
hydraulic fluids. This scale consisted of mea¬ 
suring the viscosity in centistokes at 210 F of 
a 30 (weight) per cent solution of the active 
Acryloid polymer in a standard hydrocarbon 
base stock of essentially reproducible viscosity. 
In order to judge the ability of a polymeric 
additive to improve the viscosity-temperature 
characteristics of a hydraulic fluid, a quantity 
of the active polymeric additive was dissolved 
in a quantity of hydrocarbon base stock to give 
a definite high-temperature viscosity. In the 
case of aircraft hydraulic fluids, this viscosity 
was taken to be 10 centistokes at 130 F. The 
viscosity of the fluids in centistokes at —40 F 
was then determined. The blend yielding the 
lowest viscosity at — 40 F was found to contain 
the polymer of highest molecular weight. This 
polymer was then considered to have the best 
blending efficiency. The data given below in 



LOSS OF VISCOSITY DUE TO SHEAR 


5 


Table 1 illustrate this point for polymers com¬ 
pounded from an 8-carbon atom alcohol. 


Table 1. Blending efficiency of Acryloid polymers. 


Polymer 

No. 

Relative 

molecular 

weight* 

Acryloid 
concentration 
weight per cent 

Centistoke 
viscosity at 

130 F —40 F 

1 

94 

6.5 

10 

340 

2 

84 

7.0 

10 

350 

3 

49 

8.7 

10 

380 

4 

43 

9.5 

10 

390 


* Defined as the viscosity in centistokes at 210 F of a 30 (weight) 
per cent solution of the polymer in a standard hydrocarbon base 
stock. 


The above method was found to be very suit¬ 
able for securing a relative estimate of the 
blending efficiency of Acryloid polymers. Since 
low-temperature fluidity is very desirable in 
hydraulic fluids, it was apparent that a higher 
molecular weight polymer was the most suit¬ 
able. This was also desirable from an economic 
standpoint, since it was apparent that less of 
the higher molecular weight polymer would be 
required in the hydraulic fluid. 


18 LOSS OF VISCOSITY DUE TO SHEAR 

The molecular weight of the acrylic ester 
polymer that could be used was limited, how¬ 
ever, by the tendency of the polymer molecules 
to be sheared and to decrease in apparent mo¬ 
lecular weight when subjected to excessive tur¬ 
bulence and throttling under conditions of high- 
pressure drop. Such conditions prevail to vary¬ 
ing degrees in most types of conventional 
hydraulic equipment employing high-speed 
pumps, relief valves, etc. The normal result 
of such a phenomenon was found to be a de¬ 
crease in the fluid's viscosity, the magnitude 
of which was dependent on the molecular 
weight of the Acryloid employed in the fluid. 
Thus, it became necessary to select an Acryloid 
having suitable blending efficiency, but whose 
molecular weight would not cause excessive 
viscosity decrease due to shear. A testing pro¬ 
gram was carried out in a hydraulic cycle 
consisting essentially of a hydraulic pump, 


loaded by means of a particular throttling or 
relief valve, through which the oil was cycled 
approximately 5,000 times at a pressure of 
1,200 psi and an oil temperature of 100 F. The 
data in Table 2 illustrate the effect of Acryloid 
molecular weight on the permanent viscosity 
decrease of fluids blended to approximately 10 
centistokes at 130 F. The Acryloid polymers 
were prepared from 8-carbon atom alcohols. 


Table 2. Viscosity stability under shear. 


Polymer No. 

Relative 

molecular 

weight 

(as defined above) 

Per cent decrease in 
100 F centistoke 
viscosity after 5,000 
cycles in pump test 

1 

46 

15 

2 

50 

19 

3 

63 

22 

4 

77 

25 


It was decided that 15 to 20 per cent de¬ 
crease in viscosity would not jeopardize the 
operation of hydraulic fluids. The tolerable 
Acryloid molecular weight range, therefore, 
was controlled by employing only those poly¬ 
mers meeting the requirements of a given me¬ 
chanical treatment, such as a pump test. The 
mechanical treatment of hydraulic fluids in 
various types of hydraulic pumps was under¬ 
taken to define more clearly the extent of per¬ 
manent viscosity decrease due to shear under 
various test conditions. Table 3 below gives 
the range of values of permanent viscosity de¬ 
crease, obtained in different units with a typi¬ 
cal specification AN-VV-0-366b (aircraft-type) 
hydraulic fluid. Each unit was pressure-loaded 
by means of a balanced-type relief valve. 

Because of the increasing tendency towards 
high-pressure operation (3,000 psi) work was 
devoted to the study of more stable polymers. 
In no case, however, did the viscosity decreases 
listed above hamper the satisfactory operation 
of the test unit. The mechanical tests proved 
suitable for judging the shearing action of hy¬ 
draulic pumps and valves, as well as evaluating 
the suitability of the Acryloid or polybutene 
polymers. 

During the course of the work, it was found 
that the polymer-containing hydraulic fluids 
















6 


HYDRAULIC FLUIDS 


would incur a temporary decrease in viscosity 
when subjected to extremely high-shearing 
stress in small capillaries or small clearances, 
usually under the influence of high-pressure 

Table 3. Viscosity decrease due to shear in pump 
units.* 


Per cent decrease in viscosity in centistokes 
at 100 F after 5,000 cycles through unit 


Type of 
Pump 

Hydraulic 

pump 

alone 

Vickers 

relief 

valve 

Total for 
pump and re¬ 
lief valve 

1,000 

psi 

3,000 

psi 

1,000 

psi 

3,000 

psi 

1,000 

psi 

3,000 

psi 

Pesco gear 

10 

17 

20 

27 

30 

44 

Dowty piston 

6 

15 

20 

28 

26 

43 

Vickers piston 

4 

16 

23 

26 

27 

42 

Hycon piston 

3 

5 

25 

35 

28 

38 


* Test conditions: Oil temperatures 100 to 200 F; operating pres¬ 
sure of 1,000 and 3,000 psi and a pump speed of 3,600 rpm. 


drop. This property could be measured quanti¬ 
tatively in small capillaries and was also evi¬ 
denced by slight increases in internal fluid leak¬ 
age past close-fitting parts such as pistons and 
valve plates, caused by this temporary de¬ 
crease in fluid viscosity. Both polybutene and 
Acryloid blended fluids displayed this behavior. 
The magnitude of this temporary viscosity de¬ 
crease was found to be dependent upon polymer 
molecular weight and concentration and also 
fluid viscosity. Molecular weight appeared to 
be the controlling factor. The effect upon in¬ 
ternal leakage was at no time harmful to the 
satisfactory operation of any hydraulic unit. 
The control of permanent viscosity breakdown 
by mechanical means was considered adequate 
for limiting the extent of the temporary vis¬ 
cosity decrease that prevailed under very high 
rates of shear, i.e., of the order of 0.5 million 
reciprocal seconds. 

As the different chemical, physical, and me¬ 
chanical phases of this project developed, it 
became evident that it would be possible to 
produce a polymer-containing fluid suitable for 
hydraulic systems. An aircraft hydraulic fluid 
could be made to have a high-temperature vis¬ 
cosity adequate to meet the most severe operat¬ 


ing requirements and adverse leakage condi¬ 
tions. The viscosity at — 40 F could be as low 
as 200 to 300 centistokes, which is very much 
lower than the value of 7,000 centistokes for 
the 3580-type fluid used in 1941. The new fluid 
could be prepared with a pour point of —80 F 
and a flash point above 270 F, and these prop¬ 
erties were at least as good or better than 
those in the previous 3580 fluid. In addition, 
it was found that many other properties could 
be incorporated into the basic formula without 
sacrificing or jeopardizing other important fea¬ 
tures that were needed. To obtain these prop¬ 
erties, however, it was necessary to utilize new 
types of petroleum base stocks, for they con¬ 
tributed many important properties to the fin¬ 
ished fluid. Subsequent work showed that the 
concentration of the proper type of polymer 
need only be in the range of 5 to 15 weight 
per cent. Petroleum stocks could therefore be 
used to provide the bulk of the needed materi¬ 
als for these improved fluids. Their cost would 
also be very materially lower. 


19 BASE STOCKS 

A comprehensive study of methods for se¬ 
curing suitable petroleum base stocks was un¬ 
dertaken. It was found that some of the exist¬ 
ing manufacturing processes could be simpli¬ 
fied, and that some of the anticipated problems 
could be averted. For example, in order to 
obtain petroleum fractions free from solids at 
temperatures of the order of —80 F, it was 
thought at first that thorough dewaxing would 
have to be carried out. Such a process would 
be laborious, expensive, and, above all, it would 
interfere seriously with the rapid production 
of these needed stocks because an extensive re¬ 
search and development program would have 
to be completed to learn how to dewax at these 
temperatures, since this had never been done 
before. If this dewaxing had to be done, con¬ 
siderable additional plant facilities and ma¬ 
chinery, such as compressors, heat exchangers, 
filters, and other pieces of mechanical equip¬ 
ment, very much in demand by other war 
projects, would have been required. These dif¬ 
ficulties might have delayed production seri- 
















DEVELOPMENT OF FINAL FLUIDS 


7 


ously. However, upon more thorough exami¬ 
nation of various crude oils, it was found that 
there were ample stocks of the so-called wax- 
free or naphthenic crudes which could be util¬ 
ized if they could be given some additional 
refinery treatment. This related to removing 
the aromatic-type hydrocarbons which are in¬ 
variably found in such crudes. Aromatic hydro¬ 
carbons are particularly deleterious to the syn¬ 
thetic rubbers, which are used for making all 
sorts of seals in hydraulic equipment. The 
elimination of these aromatic hydrocarbons at 
extremely low temperatures proved to be a 
simpler process than dewaxing. In addition, 
considerable “know-how” was available on 
these dearomatization processes, which con¬ 
sisted of either solvent-extracting the desired 
petroleum fraction, or treating it with sulfuric 
acid, or both. It was found that the aromatic 
content of stocks so treated could be controlled 
by evaluating the aniline point, and the aniline 
point change, using a standardized laboratory 
acid-extraction procedure. 

Briefly, the preparation of a finished suitable 
base stock from a typical refinery virgin gas 
oil or fuel oil requires the use of at least four 
of the following steps, carried out in approxi¬ 
mately the order listed: (1) preliminary chem¬ 
ical treatment to remove deleterious substances 
such as naphthenic acids, phenols, nitrogen 
bases, sulfur compounds; (2) distillation to 
produce the required viscosity and volatility 
so that evaporation and inflammability require¬ 
ments could be met; (3) dewaxing if there was 
insoluble material at low temperatures, but 
this step, as indicated, is normally not em¬ 
ployed; (4) dearomatization to eliminate the 
aromatic-type hydrocarbon harmful to syn¬ 
thetic rubbers; and (5) clay filtering and blot¬ 
ter pressing to remove any contamination in¬ 
troduced by any of the previous physical or 
chemical operations. 


110 DEVELOPMENT OF FINAL FLUIDS 

Once the general plan and procedure for 
making these improved hydraulic fluids was 
clear, the specific details were worked out 
methodically with careful attention to the 


availability of the most suitable and effective 
ingredients in order to obtain the optimum 
combination yielding the best overall proper¬ 
ties in the finished fluid. An aircraft hydraulic 
fluid specification was prepared (AN-VV-O- 
366a, August 6, 1942), providing for the 
measurement and control of over 20 different 
properties of the fluid. Commercially prepared 
fluids meeting this specification were pre¬ 
pared without serious difficulty and delivered 
promptly. 11 

The improved hydraulic oil for Army Ord¬ 
nance is described in specification AXS-808 
(September 9, 1942). The excellent perform¬ 
ance of the aircraft-type fluid in Alaska dur¬ 
ing the winter of 1942-1943 was reported by 
the AAF in March of 1943. 8 Army Ordnance 
carried out extensive firing tests on recoil oil 
AXS-808 during the winter of 1942-1943 at 
The Proving Center, Winter Detachment, Camp 
Shilo, Canada. The results are given in Army 
Ordnance report No. RLD 6-1. It was recom¬ 
mended that this oil replace those used earlier, 
and that all future design of recoil mechanisms 
be based on AXS-808 fluid. 

Extensive research and development work 
was also carried out on an improved Navy 
ordnance hydraulic fluid. This culminated in 
the issuance of Navy Specification O.S. 2943 
(March 25, 1943). Later (August 1943), a 
complete revision of another Navy hydraulic 
oil was made to correct all the deficiencies of 
this older oil and to bring it up to date with 
the new developments in hydraulic fluids. This 
resulted in a completely revised form of Navy 
Ordnance Specification O.S. 1113 for hydraulic 
oil. 

The development of these three hydraulic 
fluids led to requests for other low-tempera¬ 
ture fluids for use in compasses, and some spe¬ 
cial compass fluids were developed and pro¬ 
duced for the Army Signal Corps. At the same 
time there were requests for improved damp¬ 
ing fluids which were necessary in new fire- 

a In addition to being adopted by the U. S. Army and 
Navy, this same fluid was adopted by the Canadian Air 
Force. The Canadian specification is 3GP12 (September 
7, 1942). The British Ministry of Aircraft Production 
also adopted in its entirety the AN-VV-0-366b speci¬ 
fication, the British specification being known as DTD- 
585. 




8 


HYDRAULIC FLUIDS 


control and range-finding equipment being de¬ 
veloped by Navy Ordnance. Several damping 
fluids were prepared which were successful. 
They solved problems which otherwise would 
have required much more extensive mechani¬ 
cal and electrical changes in this fire-control 
and directional equipment. These damping 
fluids, for the most part, are extremely viscous 
fluids of a very low volatility with exception¬ 
ally flat viscosity-temperature curves. Some of 
them are prepared by dissolving carefully se¬ 
lected polymers in an ester base stock, such as 
2-ethylhexyl sebacate, and incorporating other 
additives to prevent oxidation, corrosion, etc. 
Approximately 1,800 gallons of three different 
types of damping fluid were prepared by the 
project and consigned to industry as directed 
by the Navy Bureau of Ordnance. These damp¬ 
ing fluids are designated as PRL 1866, PRL- 
Ac-239, and PRL 1700. 11 In order to get pro¬ 
duction promptly and to insure the proper 
quality of these damping fluids, it was found 
expedient to have them prepared as part of 
the project. 


111 TACKINESS 

In order that adequate quantities of the 
Army, Navy, and Air Force fluids could be 
made available at a time when supply was of 
paramount importance, the specifications were 
formulated as a sort of compromise between 
fluid availability and quality. For example, the 
flash point on the aircraft fluid was placed 
at 200 F because this value was most con¬ 
sistent with production of base stock in re¬ 
fineries, even though flash points 70 F higher 
could be produced in laboratory and pilot plant 
equipment. This increased volatility made it 
necessary to put additional emphasis on the 
evaporation characteristics so that when thin 
films of these hydraulic fluids were evaporated 
tacky residues would not be formed. When 
base stocks are too volatile, such tacky films 
form, because the polymer is being concen¬ 
trated in them through the loss of base stock 
by evaporation. To overcome this, it was nec¬ 
essary to have present in the finished fluid a 
certain amount of a relatively nonvolatile oil 


so that the evaporated films were oily and not 
tacky. This was accomplished by having 25 
per cent, or more, of a relatively high-boiling 
and nonvolatile oil present in the finished fluid. 
This expedient eliminated most of the difficul¬ 
ties that might otherwise have been encoun¬ 
tered. Tacky or sticky oil films might have 
caused delicate mechanisms, such as valves and 
hydraulic controls, to become sluggish or fail 
to move, since many of these operate with very 
small forces. 


112 GASKETS 

The problem originally assigned by the Air 
Forces included the development of gasket ma¬ 
terials. Because of the impracticability of re¬ 
placing the gaskets in the hydraulic systems 
of many existing airplanes, it was considered 
more expedient to require that the new fluid 
be operable with the gaskets then in use. 
For this reason the specifications defined the 
minimum swelling and shrinkage that would 
be tolerated by all types of rubber sealing 
media. As an additional control, the aniline 
point and aniline point change were incorpo¬ 
rated into the specification to limit the con¬ 
centration of aromatic hydrocarbons that 
would be tolerated in the finished fluids, since it 
was found that these hydrocarbons were much 
more harmful to the rubbers than the paraffinic 
or naphthenic types. Experience showed that 
fluids compatible with the rubbers then in use 
could be produced satisfactorily. Accordingly, 
this type of control was extended to the Army 
Ordnance and Navy Ordnance hydraulic fluids. 


113 SUMMARY OF SPECIFICATIONS 

Table 4 summarizes the specifications of the 
new hydraulic and recoil oils. It also compares 
the properties of the new aircraft oil (AN- 
VV-0-366b) with that of the previous aircraft 
hydraulic oil known as specification 3580. It 
should be noted that the latter two oils have 
the same viscosity at 130 F. Above this tem¬ 
perature the AN-VV-0-366b oil is more viscous. 
This is desired in order to improve lubrication, 



BLENDING PROCEDURE 


9 


reduce leakage, and permit hydraulic pumps to 
operate at pressures up to 3,000 psi. Below 130 
F the new aircraft oil becomes less viscous as 
the temperature is decreased. This is also 
desired because it improves the low-tempera- 


114 BLENDING PROCEDURE 

The procedure in blending the petroleum base 
stock with Acryloid to produce an oil meeting 
the viscosity-temperature requirements of AN- 


Table 4. Summary of hydraulic fluid specifications. 


Property 

Aircraft 
hydraulic oil 
3580-C 

Aircraft 
hydraulic oil 
AN-VV-0-366b 

Navy hydraulic 
gear oil 

O.S. 2943 

Army recoil 
oil AXS-808 
Rev. 1 

Min. Centistokes at +210 F 

(4.2) 

(5) 

10 

15 

Min. Centistokes at 130 F 

(10) 

(10) 

(19) 

(35) 

Min. Centistokes at +100 F 

18.5 

(14) 

27 

55 

Max. Centistokes at 0 F 

(500) 

(100) 

215 

(730-820) 

Max. Centistokes at — 25 F 

(2200) 

(260) 

600 

(2600-3200) 

Centistokes at — 30 F 

(3000) 

(320) 

(750) 

(3400-4400) 

Max. Centistokes at — 40 F 

(7000) 

500 

(1200) 

(6700-9500) 

ASTM slope 

(0.73) 

0.56 

0.45 

0.49 

Approx, viscosity index 

155 

225 

190 

165 

Min. flash point (C.O.C.), F 

280 

200 

225 

210 

Min. fire point (C.O.C.), F 


(210) 

235 

220 

Max. cloud point, F 


-65 

-35 

-40 

Max. pour point, F 

-50 

-75 

-40 

-50 

Max. shear breakdown, per cent 


15 

25 

25* 


* As compared to 25 in reference oil. Values in parentheses are approximate. 


ture performance of equipment operated by 
this oil. The reduction in low-temperature 
viscosity is evidenced by comparing the two 
viscosities at —40 F. In the case of the 3580 oil, 
the value is around 7,000 centistokes, whereas 
for the AN-VV-0-366b oil the specification re¬ 
quires that the viscosity be less than 500 centi¬ 
stokes. The effect of this decreased viscosity 
on performance will be outlined subsequently. 
The ASTM slope listed is the actual negative 
slope on the ASTM special viscosity graph 
paper designated as D341-39 of a straight line 
drawn between the points on the actual vis¬ 
cosity curve at — 40 F and at 130 F. The vis¬ 
cosity index is also tabulated for comparative 
purposes, but it has doubtful meaning in this 
higher range. As already mentioned, speci¬ 
fication AN-VV-0-366b represents a compro¬ 
mise between the best fluid which can be made 
and one which is relatively easy to prepare and 
produce in quantity. With existing refinery 
equipment to produce the base stocks and with 
the available Acryloid types, it is possible to 
produce a similar fluid with a maximum of 500 
centistokes at — 60 F in place of —40 F. 


K 

E 












m 



F 




P 

_ 



























































L 




o 

4 













t 


A - TYPICAL ANTI-TACK COMPONENT 
B - FRACTIONATED BASE OIL 






CF- BLENDS WITH POLYBUTENE B- 
CE- BLENDS WITH ACRYLOID HF 
P- SPEC. 3560 (UNIVIS 40) 

KL - LINE OF CONSTANT VISCOSITY 
500 CENTISTOKES AT-40 F 

■12 




t 


Oh 




V 














0.40 0.48 0.56 0.64 0.72 0.80 0.88 


SLOPE ON A STM VISCOSITY-TEMPERATURE CHART 
FOR THE INTERVAL OF - 40 TO ISO F 

Figure 1 . Effect of polymer addition in the 
blending of hydraulic fluids. 


VV-0-366b is illustrated in Figure 1. The vis¬ 
cosity at 130 F is plotted versus the ASTM 
slope on semi-logarithmic graph paper. Point 
C represents the blend of the light base stock B 













































10 


HYDRAULIC FLUIDS 


with the anti-tack component A having a flash 
point of 300 F or higher. Addition of polymer 
causes the point representing the mixture to 
move upward and to the left along lines CE or 
CF, depending on whether Acryloid or poly¬ 
butene is used as the polymeric additive. AN- 
VV-0-366b hydraulic fluids must have a vis¬ 
cosity at 130 F of more than 10 centistokes, 
and at —40 F of less than 500 centistokes. 
Line KL represents the latter requirement. It 
is evident that a fluid meeting the viscosity re¬ 
quirement of AN-VV-0-366b oil must lie within 
the shaded area of this figure. In other words, 
starting, for example, at point C , the ASTM 
slope is decreased by the addition of polymer 
along the line CE, or along line CF. For the 
particular base stock illustrated, and designated 
as C, it can be seen that the viscosity-tempera¬ 
ture requirements can be attained in this case 
using the Acryloid polymer but not with poly¬ 
butene. It is also evident that if the viscosity 
of the base stock were somewhat lower, poly¬ 
butene could provide the required viscosity- 
temperature characteristics. Point P typifies a 
fluid of the 3580 type. 


115 SERVICE PERFORMANCE 

One important criterion for judging the value 
of these new hydraulic fluids is obtained by 
analyzing their service behavior. The National 
Research Council of Canada obtained compara¬ 
tive data on the rotation of a Bristol gun turret 
and a Frazier-Nash turret, and on the depres¬ 
sion of a Bristol gun and that of a Frazier-Nash 
gun. 7 These data were obtained in a low-tem¬ 
perature altitude chamber. Records were made 
of rotation and depression times when employ¬ 
ing first a fluid designated as DTD-44-D and 
secondly AN-VV-0-366a fluid. The former is 
similar to the old 3580 fluid and matches the 
viscosity of the AN-VV-0-366a fluid at about 
130 F. Figure 2 typifies the data obtained on 
the rotation of the Bristol gun. With the older 
type of fluid, the gun was essentially inoperable 
at —35 F, and the rotation time was excessive 
when starting from the cold at —20 F. The use 
of the AN-VV-0-366a fluid made the gun oper¬ 
able at any temperature normally encountered, 


even at high altitudes. Although the new fluid 
cannot be claimed to be phenomenally better 
than the old one, the improvement is sufficient 
to make the difference between the gun’s work¬ 
ing and not working. 



O -10 -2-0 -30 -40 -50 -60 -70 

TEMPERATURE - F 


A - DTD -44D FLUID AT START. NO PREVIOUS RUNNING 
C - AN-VVO-366a FLUID AT START, NO PREVIOUS RUNNING 
B - DTD- 44D FLUID AFTER RUNNING 20 MINUTES 
E - AN-WO-366a FLUID AFTER RUNNING 20 MINUTES 
(DATA FROM NATIONAL RESEARCH COUNCIL OF CANADA) 

Figure 2. Effect of improved hydraulic fluids on 
the time of rotation of a Bristol gun. 

Tests with other aircraft equipment at low 
temperatures showed similar results. Cold- 
room tests with Sperry upper local turret using 
a Vickers drive unit and a standard shunt 
motor showed that the minimum starting 
temperature with 3580 oil was 0 F. Using AN- 
VV-0-366a fluid, starting was possible at —70 
F. The same unit with a pre-excited field shunt 
motor started at 0 F or above with the 3580 
oil and at —70 F or above with the AN-VV-O- 
366a fluid. Using a compound wound motor on 
the same installation, the torque was so in¬ 
creased that the starting temperatures were 
lowered to —55 and —100 F, respectively. 
The AAF reported 8 the excellent results that 
were obtained with the new fluid in Alaska dur¬ 
ing the winter of 1942-1943. In addition to 
these low-temperature tests, samples of used 
oils from different aircraft have been obtained 
and analyzed carefully. In each case it was 
found that there was very little change occur- 























NONINFLAMMABLE FLUIDS 


11 


ring in the fluid. There was every reason to 
believe that it would have a very long service 
life. Such data are important in determining 
whether the viscosity-shear properties, oxida¬ 
tion stability, evaporation characteristics, etc., 
have been adequately provided for in these 
specifications. 

The recoil oil AXS-808 11 was tested in 37-, 
75-, and 155-mm guns, 75- and 155-mm howitz¬ 
ers, and 3-in. and 90-mm antiaircraft guns. In 
nearly 100,000 rounds of proof firing its per¬ 
formance was satisfactory throughout a tem¬ 
perature range of —40 to +150 F. This oil 
made it possible to consolidate several Army 
Ordnance specifications for recoil and hydraulic 
oils. 

Extensive laboratory and service tests were 
also conducted on the new Navy Ordnance 
hydraulic oil O.S. 2943 and the revised form 
of O.S. 1113 hydraulic oil. These tests showed 
that the former oil would permit operation of 
hydraulic drives on guns at temperatures that 
were from 30 to 40 F lower than with the O.S. 
1113 oil. At elevated temperatures, the O.S. 
2943 oil performed at least as satisfactorily as 
the O.S. 1113 oil. The Navy employed both 
hydraulic oils because at the start of the work 
it was not possible to get the required quantity 
of the O.S. 2943 oil. The new Navy hydraulic 
oils produced better operation of the hydraulic 
equipment, retarded or prevented rusting, and 
extended materially the time between shut¬ 
down or cleaning periods. These Navy hydraulic 
oils contained about 1 per cent of tricresyl 
phosphate. This was used as an anti-seize addi¬ 
tive if close-fitting mechanical parts tend to 
weld together under severe usage. 


116 NONINFLAMMABLE FLUIDS 

Initially the main emphasis was on the de¬ 
velopment of hydrocarbon base fluids. There 
were two reasons for this. First, there was a 
critical demand for an improved fluid. The early 
work showed considerable promise; it indicated 
that this approach was the one most apt to 
succeed in the shortest possible time. Second, 
the Air Forces stated that they wished to retain 
hydrocarbon base fluids which would not 


only be miscible with the previous fluids then 
widely used, but which would also be operable 
in contact with the gasket materials and other 
sealing devices installed in the many thousand 
airplanes in the field. In other words, it was 
imperative that the problems relating to the 
deficiencies in the hydraulic fluids used at that 
time be solved promptly, with no change in the 
actual hydraulic systems. 

The principal, if not the only disadvantage 
of a hydrocarbon base fluid is its inflammabil¬ 
ity. This property has caused considerable con¬ 
cern at various times and there have been sev¬ 
eral requests from the Services for a noninflam¬ 
mable fluid. It proved particularly difficult to 
obtain objective data on the real importance of 
having a noninflammable fluid. It is not yet 
known whether the substitution of such a fluid 
for the present oil would reduce significantly 
fire hazards in airplanes and other fire losses. 
Laboratory tests of inflammability appeared to 
be of little value since carbon tetrachloride can 
be made to burn under favorable conditions, 
whereas an incendiary bullet passing through a 
metal container of the present hydrocarbon 
base hydraulic fluid will not cause a fire if the 
container is not under pressure and if the in¬ 
cendiary passes below the liquid level. Frag¬ 
mentary data from the field indicated that air¬ 
craft fires resulted in losses which would not 
have occurred if the fluid had been completely 
noninflammable. An informal report from an 
operations analysis group studying bomber 
losses by the Eighth Air Force indicated that 
about 4 per cent of the losses incurred during 
the last half of 1944 would have been avoided 
if the hydraulic fluid had been noninflammable. 
Although this percentage is not high, it indi¬ 
cated that, if the figures were reliable, a non- 
inflammable fluid would have saved 5 to 10 
bombers and their crews per month during the 
last half of 1944. Because of these reports the 
experimental work included a considerable ef¬ 
fort directed toward the development of a non- 
inflammable fluid and one that could be made 
available promptly. Although the results have 
shown promise, it has not yet been possible to 
produce a fluid of this type fulfilling all of the 
various requirements which must be met and 
which, with the exception of the inflammabil- 



12 


HYDRAULIC FLUIDS 


ity, are contained in the present specifications 
for hydrocarbon base fluids. 

The newer silicone oils are much less inflam¬ 
mable than hydrocarbon oils. However, they 
lack good lubricating properties for steel on 
steel under adverse operating conditions; they 
tend to creep more on metals and so there is 
usually more leakage in the hydraulic system; 
they shrink rather than swell the present 
rubbers used in hydraulic equipment (this is 
objectionable), and their oxidation products 
are much more corrosive than those from 
mineral oils. Their production was very limited. 
The chemistry involved in their manufacture 
is so complex that it would have been very 
difficult to obtain adequate supplies promptly. 

Ethylene glycol-water mixtures with various 
additives showed promise, as did ^-(methoxy- 
methoxy) ethanol and certain polyglycol-mixed 
ethers produced by the Carbide and Carbon 
Chemicals Company. Although all these are in¬ 
flammable in the strict sense of the word, they 
are considerably less inflammable, particularly 
when water is present as a component of the 
fluid, than the hydrocarbon base fluids. Triethyl 
phosphate mixtures also have relatively low 
inflammability, but this ester is readily hydro¬ 
lyzed by water to produce very corrosive 
products. A research program carried out by 
the Standard Oil Development Company with 
the support of the Bureau of Ships led to the 
development of various types of halogenated 
hydrocarbons showing some promise, but none 
met the specifications of the present hydraulic 
fluids; even these could be made to burn under 
certain conditions. An important objection is 
their toxicity. This would definitely make them 
undesirable for use in closed and confined 
spaces where hydraulic equipment is frequently 
installed. The carbon-fluorine compounds under 
development for various war uses may later be¬ 
come available in sufficient quantity to warrant 
consideration as fluids for hydraulic mechan¬ 
isms. Their properties were not studied in 
detail in this connection largely because they 
were not available in the quantities needed. 

Of the various non-hydrocarbon types stud¬ 
ied, the esters of certain dibasic acids having 
molecular weights of about 300 and higher, 
showed good viscosity-temperature properties 


and other characteristics useful in hydraulic 
fluids. A typical example is 2-ethylhexyl seba- 
cate. This ester has a viscosity of about 12 
centistokes at 100 F, a freezing point of —55 F, 
a flash point of about 440 F, and a viscosity 
index of about 150. Esters of this type may be 
employed with certain Acryloids to obtain 
viscosity indices of 180 to 200, and these 
materials appear to be good lubricants from 
many standpoints. Lubricants employing this 
ester together with certain additives are being 
developed as a special instrument oil. Many 
other laboratories are using these esters as the 
basis for making various special low-tempera¬ 
ture greases having exceptional fluidity at low 
temperatures, but without the attendant evapo¬ 
ration difficulties now present in greases 
derived from conventional mineral oils. This 
project was the first to point out the valuable 
properties of this class of esters. 

Various water-soluble organic solvents have 
shown promise, especially when mixed with 
special polymers to improve the viscosity index, 
or to reduce the ASTM slope, and to attain the 
viscosity properties which are needed. Solvents 
tested included ethylene glycol, propylene 
glycol, triethylene glycol, dimethoxy tetra- 
ethylene glycol, /?-(methoxy-methoxy) ethanol, 
and methyl carbitol. Thickeners included starch 
acetates, polyvinyl alcohols, carbowax, sodium 
carboxymethyl cellulose, and certain Acrysols 
made by Rohm and Haas. A typical water-base 
fluid, approximating the AN-VV-0-366b speci¬ 
fications, contained 33 per cent water, 51 per 
cent /Mmethoxy-methoxy) ethanol, 9 per cent 
triethylene glycol (as anti-tack agent), and 7 
per cent Acrysol. Such a fluid had a viscosity 
of 10 centistokes at +130 F and about 1,200 
centistokes at —40 F. The freezing point was 
-65 F. 


i*”- FUTURE RESEARCH 

The field of non-hydrocarbon organic and 
water-base fluids has not yet been explored 
adequately, and it is probable that continued 
effort would lead to the development of fluids 
which would have all desirable properties of 
hydrocarbon base fluids and yet have the ad- 



FUTURE RESEARCH 


13 


ditional advantage of being noninflammable. 
The record of the development of the hydro¬ 
carbon base fluids has emphasized, however, 
that the selection of a fluid with a satisfactory 
viscosity-temperature property is only a start¬ 
ing point. It may develop that the corrosion, 
evaporation, toxicity, lubrication, and other 
specific properties will be much more difficult to 
attain than in the case of the hydrocarbon base 
fluids. Work on developing higher flash or non- 
inflammable fluids meeting the present speci¬ 
fications should continue, in addition to that 


which is directed toward the perfection of the 
present fluids with respect to improvements in 
antirust properties, oxidation and shear stabil¬ 
ity, rubber swelling, tackiness and evaporation, 
foaming, leakage, lubrication, etc. The develop¬ 
ment of improved gasket materials should also 
parallel the work on the fluids, for improve¬ 
ments in some of the new high-polymer plastics 
may enable gasket materials to be manufac¬ 
tured which are insensitive to any of the fluids 
which may be subsequently employed. 



Chapter 2 

DUST REMOVAL FROM AIRCRAFT ENGINE AIR SUPPLY 


O perations in North Africa in the latter 
part of 1941 emphasized the necessity of 
removing dust and sand from the air intake of 
military aircraft engines. Under desert condi¬ 
tions aircraft were found to have a service life 
as short as 5 to 15 hours. Efficient fabric and 
metal cloth filters had been developed, but 
these required servicing or replacement, and 
introduced a serious pressure drop in the air- 
intake duct. Such filters were applicable in air 
ducts of a large cross section, but many of the 
aircraft had very small air ducts in which filter 
installation was impractical. Many aircraft 
had been sent to Africa without filters, and it 
was desired that an air-cleaning device be 
developed which might possibly be installed in 
the field. The problem was brought to the 
NDRC by the NACA in late March 1942. 

A preliminary analysis of the problem and 
discussions with the Bureau of Aeronautics and 
Naval Aircraft Factory indicated that filters 
for the purpose were in a relatively advanced 
state of development, and that much more 
could be done by the Services in adapting exist¬ 
ing filters for combat aircraft than by the 
NDRC in developing improved filter designs. 
Accordingly, work was initiated on the devel¬ 
opment of a simple device employing the prin¬ 
ciple of centrifugal separation, with the idea 
that it might either replace or complement the 
filter. 

Small-scale experimental work was carried 
out to determine the possibilities of a duct 
skimmer, a cowling skimmer, and a channel air 
filter. Half-scale tests were carried out on the 
cowling skimmer, which proved to be the most 
promising of the three small devices. The duct 
skimmer consists of a splitting vane positioned 
in the duct following a bend, with provision to 
withdraw and reject the dust-laden air collected 
along the outer curved wall. This device was 
tested quite thoroughly on a small scale, and the 
final report contains detailed data on its per¬ 
formance. It was finally rejected for several 
reasons, including the following. On idling the 


duct may be under suction, so that dust-laden 
air would not be rejected; the air velocity in 
the duct is too low to make the device operate 
efficiently when the engine is idling; it is not 
applicable to all aircraft duct designs; and it is 
less efficient than the simpler cowling skimmer. 

The channel air filter consisted of a cloth 
filter fitted diagonally lengthwise in the air 
duct, with the idea that the high-air velocity 
parallel to the filter surface would make the 
filter surface self-cleaning. A part of the air 
was withdrawn and rejected at the end of the 
cloth on the upstream side in order to maintain 
the desired high velocity over the dirty surface. 
It was found, however, that dust continued to 
build up on the cloth surface, and that rela¬ 
tively little was swept off. This led to excessive 
pressure drops with reasonable filter areas, and 
the device was abandoned. 

The cowling skimmer consisted of a vane on 
the cowling, inclined toward the rear of the 
plane and blocking the normal air passage 



Figure 1 . Cowling skimmer for removal of dust 
from aircraft engine air intake. 


directly back through the air duct (see Figure 
1). The propeller wash tended to sweep the 
dust past the vane and allow clean air to be 
drawn into the duct through a slot behind the 
up-tilted vane. The principle of this device was 
first tested by employing a tee skimmer in 
which cleaned air was withdrawn through a 
right-angle connection to a horizontal straight- 
through passage carrying dust-laden air. This 
small device was later modified to incorporate 
a tilted vane partially covering the outlet to the 


14 










DUST REMOVAL FROM AIRCRAFT ENGINE AIR SUPPLY 


15 


tee, and later a half-scale model was con¬ 
structed with a vane 5 in. wide and 31/2 in. 
from pivot to trailing edge, with the top edge 
of the vane 11/2 in* above the skin. Approach 
velocities varied from 48 to 102 ft per sec and 
velocities in the vane opening were varied from 
21 to 102 ft per sec. The data were correlated 
in such a way that only a small extrapolation 
was necessary to obtain the estimate of per¬ 
formance on a full-scale installation shown 
below. 

Condition of Estimated Cleanup Efficiency, in PerCent, 
Operation for Particles of Micron Size 

10 20 43 74 417 

(325 mesh) (200 mesh) (35 mesh) 


Take-off 

55 

71 

88 

96 

99 

Taxiing 

65 

78 

93 

98 

99 

Idling 

70 

81 

94 

99 

99 


The principal characteristics of the device 
are: 

1. Efficiency is best under conditions of low- 
engine load, when the ratio of intake-duct speed 
to propeller wash speed is low. 

2. Efficiency increases rapidly with increase 
in particle size, the device being highly efficient 
for coarse dusts. 

3. Pressure drop is low. 

4. The vane can be readily displaced to ob¬ 
tain normal intake with ram effect. 


5. The performance does not vary with use. 

6. No cleaning or servicing is required. 

7. It is conceivable that the device could be 
installed in certain planes in the field. 

8. If used with a filter, it removes the coarse 
dust which the filter has difficulty in retaining, 
and greatly reduces the required frequency of 
cleaning of the filter. 

The results of the experimental work on the 
cowling skimmer were brought to the attention 
of the NACA, the Bureau of Aeronautics, and 
Army Air Forces in late 1942, and the final 
report issued February 4, 1943. 1 By this time 
standard requirements for filter installations 
had been set up, but it was found possible to 
employ the cowling skimmer principle in vari¬ 
ous aircraft installations. The skimmer is more 
effective than the filter for the larger particle 
sizes; therefore the two are frequently em¬ 
ployed to complement each other, with air intake 
to the filter designed to bring in air in a direc¬ 
tion normal to the line of flight, and dampers 
installed to by-pass the filter and obtain the 
ram effect on air intake after take-off. The 
NDRC report was made available to aircraft 
manufacturers in order that they might see how 
best to employ the skimmer principle in con¬ 
junction with a filter installation, thus greatly 
prolonging the time interval between required 
cleanings of the filter. 



Chapter 3 

PROTECTION OF AIRCRAFT FUEL TANKS AGAINST EXPLOSION 


3i SUMMARY 

T he gasoline vapor-air mixture present in 
partially empty aircraft gasoline tanks rep¬ 
resents a serious explosion hazard at moderately 
low temperatures. To provide an inert atmos¬ 
phere, a system employing engine exhaust gas 
was installed in a C-46 airplane and was proved 
by flight tests involving rapid dives from high 
altitudes. The complete installation for a twin- 
engine aircraft such as the C-46 with a fuel 
capacity of 1,440 gallons has a total weight of 
approximately 25 pounds, and provides con¬ 
tinuous protection. 


3 2 EXPERIMENTAL WORK 

Mixtures of gasoline and air are explosive 
when the volume per cent gasoline vapor lies in 
the range of about 1.5 to 6.0. Since the air in 
the vapor space over the fuel tends to become 
saturated with gasoline at the tank tempera¬ 
ture, there is a range of operating tempera¬ 
tures over which the vapor space over the fuel 
will contain an explosive mixture. With avia¬ 
tion gasoline this temperature range is roughly 
— 9 to —29 C at atmospheric pressure and —30 
to — 50 C at 30,000 ft. Partially empty fuel 
tanks in these temperature ranges represent 
serious explosion hazards, as they carry large 
volumes of explosive gases. 

Experimental tests with both incendiary and 
ball ammunition show that the explosion of a 
fuel tank containing an explosive fuel-air mix¬ 
ture is quite violent, and that the force of the 
explosion is doubtless sufficient to wreck an air¬ 
craft in flight. Although the Services have re¬ 
ceived relatively few reports on gasoline tank 
explosions, it has been supposed that an un¬ 
known number of aircraft may have been lost 
as a result of such explosions, but the reason 
for the loss was not determined. The probabili¬ 
ty that important losses resulted from fuel tank 
explosions seemed sufficient to justify experi¬ 


mental work on the development of means for 
protecting against the occurrence of explosive 
gas mixtures in the gas space over the fuel. 

Exploratory work was carried out on the 
generation of inert gas by complete combustion 
of carbon to form nitrogen and carbon dioxide. 
A second proposal studied was the removal of 
oxygen from air by reaction with hot copper, 
and regeneration of the copper by subsequent 
reduction of the copper oxide by reaction with 
gasoline. In each instance it was planned that 
the oxygen-free gas would be fed into the fuel 
tanks to replace the gasoline withdrawn to the 
aircraft engines. 

The carbon burner was designed to use spe¬ 
cially activated carbon supplied by the Dow 
Chemical Company. This had the advantages 
of a low ignition temperature (200 C) and a 
low ash (1.5 to 3.5 per cent). It was estimated 
that the weight for carbon and generator would 
be about 90 pounds for a two-engine ship in 
normal flight. Greater weight would be neces¬ 
sary to give protection during dives. This unit 
was considered too hazardous for use because 
of the temperatures reached, which were well 
above the melting point of aluminum. If hit 
by a projectile, the results would be as serious 
as a hit on an unprotected fuel tank. No satis¬ 
factory method was developed for starting or 
stopping the operation. 

The copper regenerative unit depended on 
the removal of oxygen from the air by copper 
gauze previously activated with ferric nitrate. 
This reaction occurred at a temperature of 600 
to 700 C. The copper oxide formed was then 
reduced to the metal with gasoline vapor, re¬ 
quiring about 1 gallon of gasoline for 3,000 to 
4,000 cu ft of inert gas produced. This unit 
would be easy to start and stop, and control 
would be simple. However, the weight was con¬ 
sidered too great. It was estimated that 50 
pounds would be required to protect a two- 
engine plane (2,000-hp engines; 1,440-gallon 
fuel capacity) during level flight, and this 


16 


EXPERIMENTAL WORK 


17 


would have to be increased for protection 
during dives. 

The disadvantages of the two systems made 
them appear less promising than the use of 
inert gas obtained from the engine. Accord¬ 
ingly, the further work and flight testing were 
confined to development of the use of exhaust 
gas. Similar work was carried out simultane¬ 
ously at Farnborough in England, and the 
Russians were reported to have had a system 
using exhaust gases in operation on their 
Lagg-3 aircraft in 1943. 

Exhaust gases low in oxygen may be em- 


or to maintain ambient pressure in the tank 
during descent. In either case the hot engine 
exhaust gases must be cooled and corrosive 
constituents removed. The experimental work 
involved ground and flight testing of both sys¬ 
tems, referred to as open and closed. 

The system developed included an exhaust 
gas scoop placed inside the engine exhaust pipe, 
a heat exchanger, a flame arrester, gas lines 
to the wings, a check valve, a vacuum breaker, 
and a pressure relief valve. The general ar¬ 
rangement of these in the installation as pro¬ 
posed for a C-46 (Navy R-5-C) is shown in 



RELIEF VALVE 
DISCHARGE TO ATMOSPHERE 
BREAKER 


Figure 1. General arrangement of installation for using exhaust gases to 
provide protection for fuel tanks. 


ployed in two ways to provide protection for fuel 
tanks. The gases may be forced through the 
gas space over the fuel to purge the tanks con¬ 
tinuously, or the gases may be drawn into the 
tanks only as needed to replace the fuel used, 


Figure 1. For experimental purposes, such a 
system was set up and tested on the ground, 
using C-46 wing tanks and exhaust gas and 
cooling by propeller wash from an aircraft on 
the ground. The equipment was then placed 










18 


PROTECTION OF AIRCRAFT FUEL TANKS AGAINST EXPLOSION 


inside the fuselage of a C-46 and flight tested 
in dives from 25,000 ft. Two half-tanks were 
placed one above the other with provision to 
drain fuel from one to the other at various 
rates simulating fuel consumption by engines. 
Rotameters were employed to measure inert 


passage in such a way that cooling air passed 
over both inner and outer surfaces of the hol¬ 
low cylindrical shell carrying hot gas. This ex¬ 
changer was constructed of 18-8 stainless, and 
was so designed as to be easily taken apart for 
cleaning. The amount of exhaust gas cooled to 


— Q — r OPEN SYSTEM -©—= CLOSED SYSTEM 

— A— = OPEN SYSTEM — + * CLOSED SYSTEM 



TIME-MINUTES 


CM 

o 


LU 

o 


cc 

LU 

Ql 


Figure 2. Contrast of open system versus closed system. 


gas flow rate, and gas samples were withdrawn 
from both ends of the upper test tank. Various 
temperatures were recorded by means of ther¬ 
mocouples and careful measurements were made 
of the pressure differential between inside and 
outside of the test fuel tank. Flight test data 
were obtained with both the closed system, 
fitted with a vacuum break and pressure relief 
valves, and the open system, in which these 
valves were omitted. 

Four heat exchangers were tested and evalu¬ 
ated. The best performance was obtained from 
a cylindrical type with straight-through pas¬ 
sages for the cooling air. The hot gases were 
fed through the annular space between two con¬ 
centric cylinders forming a hollow shell. This 
shell was supported within a cylindrical air 


approximately ambient air temperature was 
roughly 3 per cent of the exhaust from one 
engine, and the pressure drop due to friction 
on the exhaust gas side of the heat exchanger 
was less than % in. of water. 

Figure 2 shows typical results of flight test¬ 
ing with both open and closed systems. The 
horizontal line at 12 per cent oxygen indicates 
the approximate composition of the lower ex¬ 
plosive limit of air-vapor mixtures, for com¬ 
parison with the gas compositions obtained in 
flight by analysis of the gas withdrawn from 
the fuel tanks. With the open system this limit 
was exceeded following a dive, because of the 
fact that the inert gas supply was inadequate 
to purge the tank under these conditions and 
air entered through the vents. With the closed 






EXPERIMENTAL WORK 


19 


system the maximum negative pressure reached 
during a dive was % in. of water, noted in one 
dive from 25,000 to 13,000 ft at a rate of 
descent averaging 2,000 ft per minute. 

The flame arrester was a conventional type 
consisting of alternate flat and corrugated flat 
sheets of cupro-nickel alloy forming a honey¬ 
comb grid. The check valve in the gas line was 
a %-in. fuel line check valve as used on the 
P-40 aircraft and served to prevent the return 
of fuel or gas from the fuel tanks. This valve 
operated under a pressure differential of less 
than % in. of water. The fuel tanks were 
standard C-46 all-riveted wing tanks cut in 
half, and contained the usual baffles, sumps, 
and bulkheads. The vacuum break was a check 
valve similar to that employed in the gas line 
to the tank, but mounted in a vertical position. 
The pressure relief valve was a modified com¬ 
mercial high-pressure relief valve. The com¬ 
plete installation for a twin-engine aircraft 
such as the C-46 with a fuel capacity of 1,440 
gallons is estimated to have a total weight of 
25 pounds. 

Considerable attention was given to the 
possibility of corrosion of various parts of the 
system by the corrosive condensate or by the 
hot gases. It was found that corrosion difficul¬ 
ties could be avoided if the scoop and heat ex¬ 
changer were made of 18-8 stainless. The fuel 
tanks were cut open after the test program was 
completed and no evidence of corrosion found. 
British tests have confirmed these observations. 

The possibility of vapor lock due to carbon 
dioxide dissolved in the fuel has been con¬ 
sidered, but British tests with fuel saturated 
with inert exhaust gas at atmospheric pressure 


show rather conclusively that vapor-lock diffi¬ 
culties are not aggravated. 

The ground and flight tests proved the inert 
exhaust gas system operable and provided suf¬ 
ficient technical background and experience to 
serve as a basis for the design of similar sys¬ 
tems for installation on combat aircraft. The 
older systems, employing liquid carbon dioxide 
in pressure bottles, provided protection for only 
a few minutes of combat, yet weighed more 
than the exhaust gas system providing continu¬ 
ous protection and requiring less servicing. The 
data seem entirely convincing in showing the 
superiority of the exhaust system over that 
using liquid carbon dioxide. 

Whether the exhaust gas system be of the 
closed or open type is apparently a question of 
secondary importance. The open system is 
simpler because it requires no vacuum break 
or pressure relief valve, but the gas cooling 
capacity of the exchanger must be greater. The 
open system requires purging before take-off 
with a half-filled tank, whereas the closed sys¬ 
tem maintains an inert gas over the fuel when 
the aircraft is on the ground with the engines 
not running. Failure of the vacuum break on 
the closed system might cause the collapse of 
the lining of a safety fuel tank. The various 
advantages and disadvantages of the two sys¬ 
tems will be clarified only by continued flight 
test of installations of both types. 

It seems possible that a small electrically 
heated catalyst might be developed for installa¬ 
tion in each tank, serving to burn out the 
oxygen of the entering air by nonexplosive re¬ 
action with gasoline vapors. No progress was 
made in following up this idea, but it may well 
form the basis of future research. 



Chapter 4 

PYROTECHNICS—FLARES; PHOTOFLASH BOMBS 


41 SUMMARY 

A study of variations in the chemical com¬ 
position of flares showed the candlepower- 
seconds obtained per gram of metal-oxidant 
mixture to be subject to little improvement. 
For antisubmarine use, a satisfactory under¬ 
water flare was developed, burning at the rate 
of 10 sec per in. with a candlepower of 60,000 
in water for the 4-in. diameter size. Colored 
flares were developed for use at high altitudes 
in tracking guided missiles, and special igniters 
produced for this and related purposes. 

Various photometric, spectrographic, and 
high-speed photographic techniques were de¬ 
veloped for the testing of photoflash bombs, 
and the instruments constructed were em¬ 
ployed in connection with AAF-Army Ord¬ 
nance development of better bombs. Bomb¬ 
casing strength was shown to be an important 
factor, and optimum designs were developed 
on the basis of the test data. The British Mk 
III aluminum dust bomb was tested and the 
principle adapted for use in improved bombs 
of United States design. 

Exploratory tests of shock-wave flashes show 
promise justifying further study. 


42 FLARES 

4-21 Introduction 

During World War II various new uses for 
flares were envisaged; for instance, as a means 
of underwater illumination and for certain 
high-altitude operations from aircraft. The 
several types of flare requested by the Services 
were sufficiently varied to require a rather 
broad investigation of the field, and this re¬ 
sulted in the development of a number of 
principles of pyrotechnic behavior which are 
perhaps applicable beyond the original bounda¬ 
ries of the investigation. 

A very difficult matter to improve was the 


light-producing efficiency of the Service stars 
and flares, although significant improvements 
in other characteristics were made with rela¬ 
tive ease. Star shells and flares are normally 
used for visual observation, and hence should 
be judged by their effect on the human eye. 
Therefore, all light measurements were made 
with a barrier-type photocell filtered to give a 
spectral sensitivity close to that of the human 
eye, so that the light units were actually eye 
units. The reference standard of illumination 
was a tungsten filament lamp, operating in the 
neighborhood of 3000 K and generating some 
4,000 candlepower. 

It was demonstrated that the efficiencies 
(candlepower-seconds per gram) are very 
nearly constant for a series of flares having 
essentially the same spectral distribution and 
percentage metal content, but that candlepower 
and burning speed could be made to vary 
widely in an inverse relation to each other by 
changes in composition of the flare mixture. 


422 The Underwater Flare 

At the time of the greatest activity of Ger¬ 
man submarines along the eastern coast of the 
United States, the Navy requested flares which 
would burn under water and illuminate or 
silhouette a submerged submarine at night. De¬ 
tection devices used on blimps gave the ap¬ 
proximate position of the submarine, but it was 
believed that visual aid would make bombing 
much more accurate. Before the development 
was completed, the German submarines had 
moved away from the coast into deep water 
and the development was stopped. The chemi¬ 
cal work was finished, however, and prelimi¬ 
nary tests made on the mechanical design. 

It was obvious that a flare to burn under 
water must carry enough oxidant in its mix¬ 
ture to burn all the metal present, if the maxi¬ 
mum efficiency of operation was to be attained. 
All mixtures studied for use in underwater 


20 


FLARES 


21 


flares employed stoichiometric mixtures of 
metal and oxidant, in recognition of this 
principle. 

Since all light-producing chemical reactions 
of an underwater flare would occur within the 
sphere of combustion that could be maintained 
immediately over the burning flare surface, 
and since the intensity of illumination would 
depend primarily upon the size of that sphere, 
an effort was made to insure complete combus¬ 
tion of the metal as near the flare surface as 
possible. This was accomplished by using finely 
divided ingredients, 200 mesh, or finer. There 
are several other advantages to the use of 
finely divided flare ingredients: the combustion 
is smoother because a more homogeneous mix¬ 
ture is obtainable; the possibility of flare fail¬ 
ure from water seepage into the cake is mini¬ 
mized, since the voids to be taken up by the 
binder are small; the resistance of the cake to 
mechanical damage is considerably increased. 

Extended tests of the Navy’s standard star 
mixture a were carried out to determine its use¬ 
fulness as an underwater flare, and it was con¬ 
cluded that the mixture was not suitable for 
such a purpose. 5 The Navy mixture character¬ 
istically began to burn with an inferior illumi¬ 
nation, and developed into a remarkably bril¬ 
liant flare after some 15 sec. Tests of the mix¬ 
ture and variations of the formula indicated 
that the primary difficulty may have been the 
paraffin binder used. It was shown that boiled 
linseed oil with a drying catalyst of powdered 
pyrolusite was generally superior to paraffin, 
shellac, or nitrocellulose as a binder. One pos¬ 
sible binder of considerable appeal was sug¬ 
gested but was never tested; namely, furfural, 
which could be mixed with the flare ingredients 
as a liquid, and allowed to polymerize after the 
flare was packed. 

When a stoichiometric nitrate metal flare 
composition employing 200-mesh ingredients 
was tested, it was found to burn too rapidly for 
the intended purpose; hence diluents were in¬ 
corporated to slow the combustion. 2 When oxy¬ 
gen-containing inert salts, such as carbonates 
or sulfate, replaced a portion of the nitrate, a 

a Aluminum (100-200 mesh), 9 per cent; barium 
nitrate, 58 per cent; magnesium (45-100 mesh), 27 per 
cent; paraffin wax, 6 per cent. 


decrease of the burning speed was satis¬ 
factorily effected. 

A flare mixture, characterized as No. 47, 
was developed, and proper conditions for its 
use were fully investigated. The formula for 
No. 47 is: 


Magnesium 

16% 

Aluminum 

12% 

Barium sulfate 

40% 

Barium nitrate 

32% 

Compounded with 


manganese dioxide 

1% 

Boiled linseed oil 

8% 


All solids 200 mesh or finer 

This mixture, properly packed and cured, 
burned with a good light in as much as 300 ft 
of water, reached its peak candlepower within 
3 or 4 sec after ignition, and burned with a 
steady flame if it was packed in a thin-walled 
casing. It formed a strong cake, so that thin- 
walled paperboard casings could be used with¬ 
out much danger of fracture of the cake by 
rough handling. If heavy casings must be used 
in the construction of a flare, barium sulfate 
should be replaced by barium carbonate, since 
flares containing the latter tend to form less 
clinker when burned in a confined space. The 
No. 47 flare had a burning speed of 10 sec per 
in., with a candlepower (4-in. diameter) of 
about 60,000 in water, or 250,000 in air. 

Preliminary tests with underwater flares in¬ 
dicated that an object on the surface or under 
water was very well silhouetted by a 4-in. di¬ 
ameter flare burning in as much as 100 ft of 
water. On a number of occasions surface 
craft, tow targets, etc., were lighted up, and in 
one instance a school of fish in 40 to 50 ft of 
water was clearly visible when the flare was 
burning at 90 ft. The surface-illuminated 
circle was about 200 ft in diameter. 


42 3 The Rocket Star 

A need developed for a fast-burning star of 
very high intensity for use as a rocket head, 
and the standard Navy star was found unsatis¬ 
factory because of its tendency to develop peak 
candlepower slowly. A stoichiometric mixture 
of magnesium metal powder and sodium 
nitrate, both 200 mesh, bound with boiled lin- 




22 


PYROTECHNICS-FLARES; PHOTOFLASH BOMBS 


seed oil, was recommended as the most brilliant 
flare mixture available. 

The flame of such a star was a deep yellow in 
color, and generated about 40,000 candlepower 
per square inch of burning surface. It burned 
at a rate of 0.2 in. per sec. If a white star with 
about the same characteristics is desired, the 
sodium nitrate should be replaced by barium 
nitrate. 


4-2 * 4 Colored Flares 

Colored flares were desired for use on the 
tail of radio-controlled bombs so that the bombs 
could be seen from the plane during the entire 
time of their descent. It was necessary that 
the flare and igniter function at altitudes up 
to 30,000 ft; that the flare have high light in¬ 
tensity so as to be plainly visible in full sun¬ 
light at the distances involved, and that it have 
a true color, so as not to be confused with 
ground lights or bombs dropped from other 
planes using a flare of a different color. This 
use required a burning time of about 1 minute 
with the size limited to 5 in. in diameter and 
5 in. in length, including the ignition device. 
Colors requested were red, yellow, white, and 
green. 

Flares which will operate under water will 
function at high altitudes, unless the low tem¬ 
peratures encountered affect their flammabil¬ 
ity. The high altitude aspect of the problem 
had, therefore, already been solved in the work 
with the underwater flare. The real difficulty 
lay in the development of clearly colored flames 
from formulas complying with the stoichio¬ 
metric requirements for maximum efficiency in 
rarefied atmosphere. 

Tests were made with yellow flares at a dis¬ 
tance of 3,500 ft between observer and flare 
to determine what intensity was required. It 
was found that, even in full sunlight, the visi¬ 
bility and color recognition of the flare were 
entirely independent of candlepower but were 
functions of the apparent size of the flare 
flame. Even the glowing clinker of an ex¬ 
tinguished flare could be seen at that distance, 
and the color was recognizable if the clinker 


was large enough to appear as more than a 
point of light. 

Final tests were made on a range of 42,000 
ft at sea level, and again it was demonstrated 
that if the flame was large enough to be seen 
as more than a point of light its color could be 
easily determined. The 42,000-ft distance was 
great enough for air absorption of light to play 
an important factor, and the colors were modi¬ 
fied considerably by selective absorption; a 
clear yellow became deep orange, and grass 
green became lime green at that distance. 
There was, however, no question as to which 
flare was red, which green, and which yellow 
when three were burned side by side. It was 
found that the red flare, producing about 
70,000 candlepower, was easily visible at 42,000 
ft. A white flare rated at 140.000 candlepower 
was near the visibility limit, apparently be¬ 
cause it burned with a much smaller flame. 

It should be pointed out that the test condi¬ 
tion, a 42,000-ft observing path at sea level, 
was extraordinarily severe since the air absorp¬ 
tion was probably 50 to 100 times as great as 
it would be over a path from an altitude of 
30,000 ft to earth. The greater air absorption 
should affect the apparent color of the flares, 
rather than apparent size and visibility. 

The problem of attaining a colored flare of 
high color purity was not particularly difficult 
when red or yellow flares were sought but be¬ 
came increasingly so as the wavelength of the 
apparent color was made shorter. There were 
two reasons for this. First, the commonest 
impurities in heavy metal salts are sodium 
salts, which produce an extremely brilliant 
yellow flame on combustion. A small yellow 
component will not greatly affect the color 
purity of the red flare, as much as 5 per cent 
of a sodium salt being needed to make the flame 
appear orange rather than red. Mere traces 
of sodium salts will, on the other hand, com¬ 
pletely destroy the green and blue flame colors, 
turning them to a sickly white. 

Second, there is a continuous spectrum back¬ 
ground to the line and band spectra that must 
be excited to produce strong color in a flame. 
The red flare-flame spectrum has a series of 
bands between 6,000 and 7,000 A wavelength, 
the yellow flare-flame spectrum has the sodium 



FLARES 


23 


line at 5,900 A, and the green flare-flame spec¬ 
trum has a band series between 5,000 and 
5,500 A. Apparently a much greater thermal 
energy is required to excite a band at 5,000 A 
than is required for a band at 6,500 A, since 
the apparent black body temperature of the 
background spectrum increases markedly as 
the wavelength of the apparent flame color 
becomes shorter; thus, the background temper¬ 
ature of the red flame will be something like 
1,700 K, while the green flame background tem¬ 
perature will approach 2,400 K. The total color 
effect of the background spectrum will be 
yellow to white and will vary in intensity as 
the fourth power of the temperature. There 
will thus be a much greater white background 
component for the green flare, as compared to 
the red, and the saturation and purity of the 
color will be of a much lower order. With the 
blue flare the background becomes so brilliant 
that it overpowers almost completely any blue 
band spectra that may appear. 

The solution to the first problem is to use 
only the purest ingredients in the preparation 
of colored flares. The second problem can be 
solved only by devising some means of pro¬ 
ducing a truly monochromatic flare, which in¬ 
volves some new method of generating light 
energy other than the classic pyrotechnic de¬ 
vices. Pyrotechnic flares are probably near 
the limit of development, so that any further 
advance of major proportions may well have 
to be based on an entirely new principle. 

The formulas recommended for use with the 
guided bombs were: 9 


Magnesium 
Aluminum 
Mg-Al alloy (50-50) 
Manganese dioxide 
Hexachloroethane 
Strontium nitrate 
Strontium carbonate 
Sodium nitrate 
Sodium carbonate 
Barium carbonate 
Potassium oxalate 
Barium nitrate 
Lactose 


Red 

Yellow 

White 

Green 

12 



16 

9 

36 

28 


1 

1 

1 

1 

8 



19 

20 




50 

45 




18 

28 




11 




32 

55 




9 


The mixed powders were compounded with 
the following amounts of boiled linseed oil: 
5, 4, Sy 2 , 2 per cent, respectively, for the four 
colors. 


All these flares had saturated colors, were 
of sufficient intensity for daylight use, and had 
a burning speed of about 15 sec per in. 


42,5 The Ignition of Star Mixtures 
and Flares 

Since there was need for stars which would 
operate under unusual conditions, considerable 
thought was given to means of igniting such 
flares. A primer system was devised which ap¬ 
peared to be certain in operation. The second- 
fire primer was a stoichiometric mixture of 
200 -mesh magnesium and sodium nitrate, bound 
with boiled linseed oil; the first fire was 75 per 
cent second fire, mixed with 25 per cent of 
meal powder. This priming system, pressed 
on the top of a flare cake which is bound with 
linseed oil, will insure ignition from a gun¬ 
powder squib flash or any larger flame. 

The actual mechanical ignition is of impor¬ 
tance at high altitudes. A Bickford-type fuze 
will usually not burn at a pressure of 0.1 at¬ 
mosphere, so any fuze train employed should 
be a pencil of a caked primer, such as that 
mentioned above. Mechanical match mixtures 
must operate at low temperatures, and it was 
found that the usual phosphorous lead-chlorate 
striker system could be used if a good quality 
glue was used as a binder, in place of the usual 
dextrin solution. All mechanisms must be de¬ 
signed for low-temperature operations and 
must allow for increased brittleness of the 
striking compounds. Two typical matches 9 
which will operate at low temperatures and in 
a vacuum were recommended to Division 5 of 
the NDRC. 

The problem of underwater ignition is some¬ 
what different. It is necessary to get ignition 
of the primer well under way before the wet- 
proof cover of the flare blows off. It was found 
that a tight, nonelastic seal would not work, 
for the high pressures developed over the 
primer from the ignition would produce an ex¬ 
plosion violent enough to shatter the flare 
cake. The best answer seemed to be to use a 
plastic seal, such as might be obtained with a 
rubber dam or vinylite membrane over the flare 
cake. 



24 


PYROTECHNICS-FLARES; PHOTOFLASH BOMBS 


43 THE PHOTOFLASH BOMB 

431 Introduction 

Most troop and supply movements near com¬ 
bat zones are made at night, and it is necessary 
to obtain clear reconnaissance photographs. 
The photoflash bomb produces the light for 
these photographs. The bomb is dropped from 
the reconnaissance plane and timed to explode 
about two-thirds of the distance to the ground. 
At the start of World War II, the bomb in use 
was a cylindrical cardboard case 6 in. in di¬ 
ameter, containing 25 pounds of flash powder 
consisting of 40 per cent potassium perchlorate, 
34 per cent granular magnesium, and 26 per 
cent granular aluminum. It produced a peak 
candlepower of about 300 X 10 6 . In order to 
obtain better ballistics, a streamlined steel 
outer case 0.06 in. thick was later used. This 
added confinement increased the peak candle- 
power to about 500 X 10 6 , although the reason 
for the improvement was not apparent at the 
time. Because of the supply situation the for¬ 
mula was changed to 54.5 per cent barium 
nitrate and 45.5 per cent magnesium-aluminum 
alloy (50-50). This composition was also pre¬ 
ferred because it was somewhat less sensitive 
than the perchlorate powder. The new powder 
produced about the same average intensity, but 
double peaks often occurred and the time to 
peak intensity was not consistent. Both of 
these last facts resulted in occasional bombs 
providing insufficient light during the time the 
camera shutter was open (0.01 sec starting 
about 0.015 sec after burst). This bomb was 
designated the M46. 


4.3.2 ^he Explosive Photoflash Powder 

A preliminary study was made with small 
(5 to 20 gram) flashes, testing all available 
oxidants, and it was concluded that potassium 
perchlorate was as satisfactory as anything 
available and practicable. In testing various 
metal powders, it was found that zirconium 
and titanium metals and their hydrides showed 
a marked catalytic effect on the speed of re¬ 
action of flash powders, and that the addition 


of 1 or 2 per cent of one of these catalysts to 
a mixture of aluminum and potassium per¬ 
chlorate powders produced an exceedingly fast¬ 
burning powder. Without the catalyst the mix¬ 
ture was decidedly inferior as a flash producer. 

Study of the powders, including the Army 
standard perchlorate powder, indicated that a 
stoichiometric mixture consisting of 38 per 
cent magnesium-aluminum alloy (50-50), with 
62 per cent potassium perchlorate was far 
superior to the standard powder in thin-walled 
bomb casings such as that of the M46. With 
any powder, stoichiometric mixtures gave the 
greatest intensity and most consistent results. 
It soon became apparent that very little further 
improvement could be made in powder compo¬ 
sitions and that any improvements would be 
made only by increasing the sensitivity of the 
powders. No recommendations were made con¬ 
cerning the titanium or zirconium catalyzed 
powders, because their extreme sensitivity 
made them practically laboratory curiosities. 


43 3 Casings of Photoflash Bombs 

Small-scale studies of perchlorate powders 
led to the belief that the effectiveness of flash 
powders depended largely upon the casings in 
which they were fired. A series of casings, 
ranging from paper bags through glass bot¬ 
tles to hand grenade blanks, provided a range 
of casing strengths, and it was found that the 
peak candlepower values increased in the cas¬ 
ing series from paper, paperboard, and wood 
to a maximum with glass bottles, and fell 
off for the hand grenade blank. 3 

A series of test bombs with steel casings was 
prepared by Army Ordnance, and was test- 
fired at Aberdeen Proving Ground. 6 The cas¬ 
ings ranged from 20 to 60 per cent of the total 
bomb weight of 50 pounds. The barium nitrate 
reached its maximum efficiency when the cas¬ 
ing was 40 to 60 per cent of the total bomb 
weight, and fell off at 20 per cent, indicating 
that a true optimum casing powder weight 
ratio existed near the 50-50 point. 

The perchlorate powder showed the best re¬ 
sults in the lightest case (20 per cent of total 
weight), indicating that only little confinement 



THE PHOTOFLASH BOMB 


25 


was desirable for this powder. The results of 
these tests are tabulated below. 


Powder 

Case 



Weight, 

Weight, 

Case 

Candlepower 

lb. 

lb. 

Thickness 

at Peak 

54.5 per cent Ba(N0 3 )2, 45.5 per cent Al-Mg alloy 

20 

30 

0.340 in. 

1,300 X 10 6 

25 

25 

0.250 

1,650 X 10 6 

30 

20 

0.182 

1,650 X 10 6 

35 

15 

0.125 

1,500 X 106 

40 

10 

0.077 

1,350 X 10 6 


40 per cent KC10 4 60 per cent Al-Mg alloy 

20 

30 

0.280 

600 X 10 6 

25 

25 

0.210 

600 X 10 6 

30 

20 

0.152 

950 X 10 6 

35 

15 

0.109 

1,100 X 10 6 

40 

10 

0.60 

1,200 X 10 6 

62 per cent KC10 4 , 

38 per cent Al-Mg alloy (stoichiometric) 

20 

30 

0.280 

950 X 10 6 

25 

25 

0.210 

1,050 X 10 6 

30 

20 

0.152 

1,600 X 10 6 

35 

15 

0.109 

1,750 X 10 6 

40 

10 

0.060 

2,000 X 10 6 


It was concluded that there is an optimum 
amount of confinement required for each type 
of flash powder for most efficient results. 

Investigations were made of the faulty be¬ 
havior of a number of experimental Army 
bomb models employing the barium nitrate 
powder in thin-walled bombs. Analysis of test¬ 
firing measurements and high-speed motion pic¬ 
tures indicated that even in the thin-walled 
bombs weak assembly points caused failures. 
The pictures showed, in some instances, bomb 
tails blowing off and bomb bodies flying away 
intact. After correction of the assembly faults 
much higher peak intensities and greater con¬ 
sistency were obtained. 


43,4 Nonexplosive Flash Powders 

The Germans used, and the British per¬ 
fected, a photoflash bomb which was very much 
safer than the flash-powder bomb, and appar¬ 
ently was as effective. 11 The device consisted 
of a bomb casing with an axial burster of high 
explosive and the remaining space in the casing 
filled with flake aluminum powder. Magnesium 
was not effective. The weight of the burster 
as used by the British was one-third that of 


the aluminum. Detonation of the burster scat¬ 
tered the aluminum as a dust cloud and ignited 
it. The principal advantages of this type of 
bomb over the classical model were that it 
was less sensitive and that the oxygen was 
supplied by the air and need not be carried 
in the bomb. High-speed motion pictures of 
the bomb flash showed that the high-explosive 
burst blew the metal into a ring, and thus the 
flash had a central dark space. This may not 
have been true when aluminized HE bursters 
were used, which perhaps accounts for the bet¬ 
ter results obtained by the British with this 
type of burster. In addition, there was con¬ 
siderable doubt whether the metal dust was 
efficiently ignited, since the flash was usually 
highly irregular in shape, yet the dust cloud 
appeared to be symmetrical. 

Only a moderate amount of work was done 
on this type of bomb, and considerable im¬ 
provement should be possible. For example, 
the size and shape of the burster appear criti¬ 
cal but have not been thoroughly investigated. 
More aluminum can perhaps be used by com¬ 
pressing it, with sulfur or other material as 
binder. 

Aluminum-sulfur mixtures were investigated 
for use as an explosive, and preliminary trials 
were made of the mixtures as photoflash com¬ 
positions. The best results were obtained with 
a mixture of 25 per cent flowers of sulfur and 
75 per cent flake aluminum. When compressed 
at 5,000 psi, the mixture form a cake of spe¬ 
cific gravity 1.85. A conical burster of about 
% the diameter of the flash composition gave 
good dispersal and ignition, and showed better 
results than the cylindrical burster. An alu¬ 
minized TNT burster was recommended. Only 
a small amount of work was done on this mix¬ 
ture and only tentative conclusions were drawn. 
The results indicated, however, that a rapid 
and high peak intensity was obtained. 

It seems unlikely that either explosive or 
dust-flash bombs can be constructed in any feas¬ 
ible size to produce much greater than 2,000 
X 10 6 candlepower at peak, so further work 
must involve some fundamentally new method 
of producing a flash. One promising lead is the 
observation that the shock wave from a high- 
explosive detonation produces an extremely in- 



26 


PYROTECHNICS-FLARES; PHOTOFLASH BOMBS 


tense flash of very short duration when it is 
made to pass through an atmosphere of argon. 
A 200-gram explosive charge has been reported 4 
to produce a peak intensity of 200 million can- 
dlepower. Preliminary tests 13 using RDX to 
produce shock-wave flashes were carried out 
just as the project was being concluded, with 
sufficiently promising results to justify further 
study of this technique. 


4 4 INSTRUMENTS AND TECHNIQUES 
4 .4.i Photographic Photometry 

Most of the prewar flash photometry was 
carried out by means of a photographic method 
which is laborious and particularly liable to 
errors arising from a large number of sources. 
Photographic photometry is scarcely applicable 
to routine proof operations, but it is quite valu¬ 
able for research and development, since it of¬ 
fers a check on the less arduous electronic 
methods of measurement. The check is valuable 
since the methods are completely different in 
principle, and are not subject to the same in¬ 
strument errors. 

The method is, briefly, the comparison of the 
blackness of images produced on a photo¬ 
graphic film by the light to be measured and 
by some standard light of known intensity. 
Since, ideally, the blackness, or density, of the 
developed photographic image increases as the 
logarithm of the amount of light striking the 
emulsion, an error of density measurement 
will produce an anti-logarithmic error of light 
value, which will assume very large propor¬ 
tions unless density errors are kept small. 

In actual practice, the ideal logarithmic re¬ 
lationship of density and amount of light is 
seldom attained; therefore the standardizing 
exposure should cover a wider illumination 
range than the flash to be measured. A stand¬ 
ard graph of the amount of light versus density 
is plotted, and values of the unknown are read 
from the curve. The usual method is to place 
a sheet of film, which varies in transparency 
from about 90 to 0.1 per cent in a known man¬ 
ner, over the film to be standardized, and to 
impress the exposure from the standard lamp 


through the graded transparency. The stand¬ 
ardized film strip will, on development, show 
a varying blackness corresponding to the vary¬ 
ing transparency of the filter strip, or “step- 
tablet”. From the known light output of the 
standard and the transparency of each step of 
the tablet, the amount of light producing each 
exposure on the standardized film is known, 
and the density-light intensity curve can be 
set up. 

Care must be taken to use the same duration 
of exposure for standard light source and un¬ 
known value. The photographic emulsion does 
not respond equally to an intense exposure of 
short duration and a faint exposure of long 
duration, though both represent the same quan¬ 
tity of light. For example, an exposure of 0.01 
foot-candle persisting for 10 sec will not nec¬ 
essarily produce the same density on the de¬ 
veloped film as 100 foot-candles for 0.001 of a 
second, although both exposures are of 0.1 foot- 
candle-second of light. 

Duplication of film processing with sufficient 
accuracy to make separate films photometri¬ 
cally comparable is not practicable; therefore 
each sheet of film should have its own stand¬ 
ardization. Variations over a single sheet of 
film may reach large proportions unless ex¬ 
treme care is taken in the processing. It is 
necessary to develop the film at a constant tem¬ 
perature (a tolerance of dtO.l C is recom¬ 
mended), fresh developer must be used for 
each film, and the film must be brushed 
throughout development with a camel's hair 
brush to insure uniformity. A good film-proc¬ 
essing technique can only be attained by ex¬ 
tended practice. 

The latent image produced by the exposure 
varies in developability with time; hence, the 
standard wedge pattern should be impressed 
as soon as possible after the exposure of the 
film to the light to be measured. An error of 
as much as 25 per cent may be produced if 
this precaution is not heeded. There is some 
evidence that the temperature of the film at 
the time of exposure affects the results; al¬ 
though the magnitude of this effect is not well 
established, it is wise to maintain as uniform 
a film temperature during exposure as is prac¬ 
ticable. 



INSTRUMENTS AND TECHNIQUES 


27 


4 4 2 Photometry with the Oscillograph 

The use of a photoelectric cell and oscillo¬ 
graph as a photometer results in a simple and 
accurate means of determining the light-pro¬ 
ducing characteristics of a flash. Satisfactory 
oscillographs are commercially available, and 
only a few precautions need be observed in 
their use. When a photoelectric cell is coupled 
directly, or through an amplifier, across the 
deflection plates of an oscillograph, a light 
pulse directed on the photocell will give rise to 
a voltage change in the circuit. This voltage 
change will produce a deflection of the electron 
beam of the oscillograph tube proportional to 
the magnitude of the change, which in turn is 
proportional to the intensity of the light pulse. 
If the deflection sensitivity of the oscillograph 
is calibrated in terms of a standard lamp, the 
intensity of the light source in candlepower 
can be determined. 

The usual procedure of recording data is 
by some photographic method. The oscillo¬ 
graph can be made to sweep on a time axis 
perpendicular to the light intensity axis, either 
for a single sweep greater in duration than 
the period of the pulse, or in a continuous saw¬ 
tooth sweep of short duration relative to that 
of the flash. In the first instance, a straight¬ 
forward time-intensity curve will be photo¬ 
graphed, while in the second a folded curve 
will be produced. A third recording method 
employs the oscillograph without a time sweep, 
and photographs the intensity sweep on a mov¬ 
ing film to produce a time axis. 

For accurate results the photocell must be 
of the electron emission type; the barrier-type 
cells react so slowly to a sharp light flash that 
they tend to act ballistically, and give a badly 
distorted frequency response, which results in 
a false time-intensity curve. Furthermore, the 
barrier cell is so insensitive that its output 
must be amplified, and obvious difficulties are 
encountered when the direct-current light cell 
is operated through an alternating-current am¬ 
plifier. 

The greatest advantage of the photographic 
technique of photometry is that the light unit 
is defined in terms of the spectral sensitivity 
of the photographic emulsion. If the oscillo¬ 


graphic photometer is to be used, the spectral 
sensitivity of the photocell should be corrected 
to that of the photographic emulsion for ac¬ 
curate results in the study of light flashes to 
be used in photography. The correction can 
best be accomplished by means of color filters, 
although these filters are by no means easy to 
devise. 

The cesium oxide photoelectric cell is prob¬ 
ably the most satisfactory type available for 
use with the oscillograph in flash studies. Two 
photocells were used in this work, both cesium 
oxide emission cells of about the same spectral 
sensitivity. They were the RCA 919 and the 
Cetron CE-31-V cells, which showed peaks of 
sensitivity in the near ultraviolet and near 
infrared. A filter solution with high trans¬ 
mission between 6,400 and 4,000 A was used 
with these cells, causing them to correspond 
roughly in sensitivity to tri-X-panchromatic 
emulsion in the visible region. Extensive tests 
demonstrated that candlepower results, using 
the photographic photometer with tri-X-pan 
and the filter-photoelectric cell-oscillograph 
photometer, are comparable over a wide range 
of temperatures. The filter solution for the 
correction of these cells was used in a 1-cm 
glass cell. It had the following composition: 
Copper nitrate, cp Cu(N0 3 ) 2 * 3H 2 0, 60.4 

grams, dissolved in 1 liter of a solution of 
methyl alcohol, cp absolute, 60 per cent by 
volume, and distilled water, 40 per cent by 
volume. 


44,3 Spectrographic Studies of Flashes 

Only preliminary spectrographic studies of 
flashes were made in the photoflash program, 
but enough was learned to point up some of 
the difficulties of such work. For spectrophoto- 
metric use the data must be of the highest pre¬ 
cision, at the very limit of the present tech¬ 
niques of photographic photometry. For in¬ 
stance, color-temperature measurements by the 
spectrographic method are probably not better 
in precision and accuracy than ±3 per cent. 
The only other method at present in use em¬ 
ploying color filters in front of photocells of 
two channels of an oscillograph is probably 



28 


PYROTECHNICS-FLARES; PHOTOFLASH BOMBS 


better when used to measure a light pulse with 
a completely continuous spectrum, but is not 
likely to be dependable for the study of flashes 
whose spectra contain lines and bands. The 
color filters are generally transparent over a 
500 A wavelength range, and vary in trans¬ 
parency from point to point within that range, 
so that it is difficult to assign a mean wave¬ 
length to the filter for calculation purposes. 
The wide wave bands measured are likely to 
pass some of the discrete spectrum of the flash, 
which may lead to inaccurate results, since the 
calculations are based on a continuous black 
body spectrum. 

An attractive scheme for temperature mea¬ 
surement is the use of a two-channel oscillo¬ 
graph coupled to a pair of photomultiplier 
tubes, which, in turn, are placed at the exit 
slits of two monochromators set to the desired 
wavelengths. The flash is picked up by the 
monochromators, and two time-intensity curves 
drawn on the oscillograph screen, one for each 
of the wavelengths desired for calculation. 

For general studies of spectral distribution 
of flashes, the spectrograph seems to be the 
only feasible method if any detail of the spectra 
is of interest. A moving film spectrograph was 
used in this work. 


444 High-Speed Photography 

One of the most fruitful techniques for the 
study of photoflash bombs has been the high¬ 
speed motion picture camera. Cameras operat¬ 
ing at a maximum of from 2,500 to 8,000 
frames a second are commercially available, 
and are much more satisfactory for flash stud¬ 
ies than for nonluminous objects. The ideal 
camera for flash work would operate at 10,000 
frames per second, and would have a lens aper¬ 
ture variable from f/2 to //100. The commer¬ 
cial 8,000-frame-per-second camera, running at 
full speed, and //16 aperture gives pictures of 
flashes that are badly overexposed with black 
and white films. Color film with daylight sensi¬ 
tization is best suited to the work if optimum 
exposure is desired. 

Frequently a flash will yield an abnormally 
shaped time-intensity curve, presumably the 


result of deviation from the usual nonspherical 
burst. High-speed motion pictures, especially 
when projected, often show what produced the 
abnormality. Faults discovered from time- 
intensity curves can often be corrected by a 
trial-and-error method, but the cost in time 
and materials is likely to be many times the 
investment in a high-speed camera if a full- 
scale bomb is involved. 


44 5 Analysis of Results 

Since the photoflash bomb is intended to gen¬ 
erate an intense flash of light of short duration 
for photographic purposes, and since the photo¬ 
graphic effectiveness of the flash depends upon 
its intensity and duration, the most important 
item of data is the time-intensity curve. The 
quality of a particular flash will be judged 
primarily by its peak candlepower, with total 
duration, total amount of light, the time elapsed 
between ignition and peak, and the efficiency as 
secondary criteria. 

The U. S. Army Air Forces employ an aerial 
camera with a shutter speed of 0.01 sec for 
night photography. The shutter is actuated by 
a photocell mechanism which is tripped by the 
first light from the flash. A good flash should 
reach its peak intensity about the time the 
camera shutter is wide open, and since the 
time lag of the shutter mechanism is constant 
and reproducible, the flash bombs should, for 
best results, reach peak intensity within a 
millisecond or two of the open shutter time. 
Ideally, the flash should release the major part 
of its light within 0.03 sec after burst; any 
light produced after this time is of no use. 
In practice, full-scale flash bombs which func¬ 
tion properly concentrate about half of the 
total light within the 0.03-sec period. The re¬ 
maining half represents light produced at lower 
temperatures by natural cooling of the flash 
cloud. In a faulty flash, however, the flash 
powder may not be fully ignited at the burst, 
and may become productive in the dying pe¬ 
riod of the flash; such flashes are likely to 
show a marked diminution of peak candle- 
power. 

The efficiency of a flash is usually expressed 



INSTRUMENTS AND TECHNIQUES 


29 


as the number of candlepower-seconds per gram 
of metal contained in the powder. Magnesium 
metal apparently will produce about 40,000 
cps per gram under optimum conditions, but 
the usual figure for a full-scale flash bomb 
is 10,000 cps per gram. If the efficiency is 
much lower, especially if the flash is of ab- 


casing is of faulty construction. Frequently 
an otherwise normal flash will show a minor 
peak within 2 or 3 msec of the burst. This 
usually means that some of the ignited flash 
powder has blown out through the fuze before 
the bomb casing burst. The effect upon the 
quality of the flash is negligible, unless the 



Figure 1. Flash A. M46 photoflash. 



Figure 2. Flash B. T6E1 fuze burst. 


normally long duration, it is safe to assume tail blows off the bomb before the casing 
that the powder or bomb construction is faulty, ruptures. 

Delayed peaks, multiple peaks separated by High-speed motion pictures will usually con- 
over 0.01 sec, or peaks with flat tops persisting firm faults such as those mentioned above, 
for over 0.03 sec, usually occur when the bomb especially if pictures are taken from both front 






















30 


PYROTECHNICS—FLARES; PHOTOFLASH BOMBS 


and side. If a fault is of a rarely encountered 
type, it is doubtful if the seat of trouble will 
be located without the aid of motion pictures. 

The technique of analysis of results is il¬ 
lustrated by the accompanying Figures 1 to 4. 


origin, where a minor secondary peak occurs. 
Such a condition is of frequent occurrence and 
appears to be caused by a flash through the 
nose fuze of the bomb (A-a). This has virtu¬ 
ally no effect on the development or efficiency 



Figure 3. Flash C. T-10 flash cartridge. 




T8E1 aluminum flake bomb. 


Flash A 

The time-intensity curve is normal for ex¬ 
plosive photoflash powder, except at a near the 


of the flash, although at times a dark center 
will be produced on the bright surface if the 
nose flash is not swallowed by the main burst 
(A -b). 

















INSTRUMENTS AND TECHNIQUES 


31 


Flash B 

This flash is one of the most spectacular 
demonstrations of the effect of faults on rec¬ 
ord. A massive nose flash apparently occurred; 
although it does not show on the time-intensity 
diagram, it is clearly visible in the motion 
pictures. In addition, the tail appears to have 
blown off the bomb. A homogeneous ignition 
of the powder most certainly did not occur. 
There was, unfortunately, no motion picture 
record from the side of the flash, but a still 
picture shows two distinct bursts rather than 
the usual single globe. The burst at the nose 
developed rather slowly and was apparently 
fed with new material (B-a). The first-formed 
cloud was well cooled at the time of the de¬ 
layed main burst (B -b), and produced a 
marked shadow over the flash surface. A third 
portion of the powder exploded still later (B-c), 
and still farther behind the main cloud. Such 
occurrences have been recorded only with the 
barium nitrate class of flash powder. This 
powder is a very good one when used in the 
proper bomb case but tends to display freakish 
behavior in inadequate cases. Apparently it is 
relatively slow-burning in the open but reacts 
with extraordinary violence when heavily con¬ 
fined. 


Flash C 

The T-10 flash cartridge was badly designed, 
having a light metal case with about 6 oz of 
flash powder and an extremely heavy-duty, 
high-explosive igniter. When fired, about half 
of the powder was nicely dispersed and ignited 
by the burster, and the remainder was not dis¬ 
turbed. When half of the cartridge was later 
ignited, probably by the flame of the first flash 
and not at the primary ignition, it took off in 
rocket fashion and finally burst to produce the 
secondary peak (C -b). 

Flash D 

In general, the safe type of flash bomb, in 
which a dust cloud of metal is dispersed and 
then ignited by HE, will yield a normal-appear¬ 
ing flash curve regardless of faults. Any im¬ 
properly dispersed dust will probably not ig¬ 
nite, so only the primary flash will be noted. 
High-speed motion pictures show the charac¬ 
teristic dark center and irregular flash sur¬ 
face, which appears to be due to incomplete 
ignition rather than poor dispersal of the dust 
(D-a). 



Chapter 5 

IMPROVED INFLATION OF LIFE RAFTS AT LOW TEMPERATURES 


s-i SUMMARY 

L ife rafts with the standard carbon dioxide 
J inflation system, when cooled to —40 F, as 
can occur during high altitude flying, often re¬ 
quired well over 15 minutes for proper infla¬ 
tion. By mixing nitrogen or nitrous oxide with 
the carbon dioxide, inflation could be obtained 
in slightly less than 15 minutes if the valve 
end of the cylinder was down. If it was up, no 
improvement occurred. In actual use the posi¬ 
tion of the cylinder would be a matter of 
chance. The use of compressed air in place of 
carbon dioxide gave very satisfactory inflation, 
but larger, and therefore heavier, cylinders 
were required, which made this solution unac¬ 
ceptable. Replacement of the carbon dioxide 
with nitrous oxide gave much improvement 
with the valve end of the cylinder down, full 
inflation occurring in 6 minutes. No improve¬ 
ment was obtained with the valve end of the 
cylinder up. However, by using a modified dip 
pipe in the cylinder with the nitrous oxide, the 
improved results were obtained regardless of 
the cylinder position. This combination of the 
use of nitrous oxide and the modified dip pipe 
appeared to be the most satisfactory method of 
altering existing equipment. 


52 INTRODUCTION 

Life rafts made of rubberized fabric were 
carried on all military planes flying over water. 
These rafts were carried folded and were in¬ 
flated with carbon dioxide when they were 
needed. Several sizes of rafts and types of re¬ 
lease from the plane were used, depending on 
the number of men in the crew and the con¬ 
struction of the plane. Fighter pilots wore the 
raft as a seat pack; in the bombers the raft 
was in a separate compartment from which it 
was generally ejected by the inflation after the 
carbon dioxide release was pulled, but in some 
planes the raft was ejected mechanically. 


It was found that when the carbon dioxide 
was at a low temperature at the time of dis¬ 
charge, the raft was inflated very slowly, often 
requiring more than 15 minutes. This condition 
was serious in northern latitudes, since a man 
will generally not survive after immersion in 
cold water for this length of time. A plane is 
likely to sink within 30 sec of a crash landing, 
and if the ejection of the raft depends on the 
inflation, the slow inflation may result in loss 
of the raft. 


53 CARBON DIOXIDE SYSTEM 

If the cylinder was in an upright position 
(valve end up) when discharged, only gaseous 
carbon dioxide was emitted, leaving a large 
residue of solid carbon dioxide in the cylinder. 5 * 
With rafts at —40 to —60 F inflated in air, only 
about 45 per cent of the cylinder contents were 
discharged in 1 minute. The remaining solid 
vaporized very slowly. When inflated in water, 
about 60 per cent of the contents of the cylinder 
was discharged. If the valve of the cylinder 
was down, the contents were discharged as 
liquid and the vaporization took place in the 
valve or manifold, where solid carbon dioxide 
was formed, usually plugging the system and 
stopping the inflation within a few seconds of 
the time the valve was opened. Practically no 
inflation was obtained for several minutes. 

The life raft inflation system used a cylinder 
capable of withstanding an internal pressure of 
approximately 3,000 psi. This cylinder was 
usually charged to a density of 42.5 pounds of 

a Some cylinders were equipped with a rigid dip pipe 
extending to the bottom of the cylinder. Thus liquid dis¬ 
charge occurred when the valve end was up, and 
gaseous discharge when the valve end was down. Other 
cylinders were equipped with a short flexible dip pipe 
which gave liquid discharge both when the cylinder was 
horizontal and the valve end of the cylinder was down. 
As an aid to the visualization of the problem, the case 
of the simple cylinder with no dip pipe is used as an 
example in discussing relations applicable to all three 
cases. 



PROPOSED MODIFICATIONS 


33 


carbon dioxide per cubic foot of inside cylinder 
volume. At this density, 99.2 per cent by weight 
of the carbon dioxide was liquid at —65 F. The 
ratio of liquid to gaseous carbon dioxide pro¬ 
gressively decreased as the temperature in¬ 
creased, and became zero at the critical tem¬ 
perature of 88.4 F. 

The heat required to convert the carbon diox¬ 
ide from liquid to gas came from several 
sources: the sensible heat obtained by cooling 
liquid carbon dioxide, the cylinder, raft and 
surroundings; or from the latent heat of fusion 
liberated when the carbon dioxide solidified. 
When a cylinder at room temperature was dis¬ 
charged, the sensible heat of the liquid carbon 
dioxide and of the cylinder was sufficient to 
vaporize nearly all the carbon dioxide, so that 
only a small remainder froze. However, if the 
cylinder was initially at low temperature, the 
heat necessary to vaporize the carbon dioxide 
was almost entirely derived from the heat 
liberated by the solidification of a large frac¬ 
tion of the carbon dioxide. This resulted in only 
partial vaporization and only partial inflation 
of the raft. 

Whether the evaporation of liquid carbon 
dioxide at low temperatures occurs in the cylin¬ 
der or in the raft, a substantial quantity of the 
carbon dioxide will be solidified. In order to 
vaporize the solid, heat must be transferred 
from the surroundings to the residual material, 
and this process is very slow. The rate at which 
heat is transferred depends on three factors: 
the driving force or temperature difference, the 
area available for heat transfer, and the resis¬ 
tance to heat transfer per unit area. Applying 
these concepts to the problem of securing the 
vaporization of carbon dioxide, several con¬ 
clusions are apparent. The rate of vaporization 
of carbon dioxide will be higher if the snow is 
in the raft rather than in the cylinder, due to 
the larger area over which the snow may be 
scattered within the raft. Since resistance to 
heat transfer from air is roughly ten times as 
large as that from water, the snow will vapor¬ 
ize much faster if the raft is in the water. The 
resistance to heat transfer to a boiling liquid 
is much lower than that offered to sublimation 
of a light powder substance such as carbon 
dioxide snow. Hence, heat will be transferred 


to the liquid carbon dioxide much faster during 
the period of initial vaporization than at any 
later time. The temperature of the surround¬ 
ings will not greatly affect the rate of heat 
transfer, since the temperature difference is 
180 F and 138 F at ambient temperatures of 70 
F and 28 F. However, under the most favor¬ 
able conditions for heat transfer with snow 
inside the raft and the raft in the water, the 
time required for vaporizing the residual 
carbon dioxide snow will be measured in 
minutes and not seconds. 


54 PROPOSED MODIFICATIONS 

From this preliminary examination of the 
problem, it was apparent that the carbon diox¬ 
ide system was unsatisfactory: (1) because 
sufficient heat was not available for vaporizing 
all liquid carbon dioxide, (2) because of pas¬ 
sage plugging by solid carbon dioxide, and (3) 
because of the low rate of sublimation of the 
residual solid formed during vaporization. The 
above consideration suggested several methods 
of improving operation. 

1. Use of a material in place of carbon diox¬ 
ide that would not be liquefied at —65 F, such 
as dry-compressed air, thus eliminating the 
necessity of supplying latent heat and remov¬ 
ing the possibility of plugging of passages by 
solid. 

2. Use of material in place of carbon dioxide, 
such as nitrous oxide, which would not solidify 
under the conditions encountered, because its 
freezing point was below its boiling point at 1 
atmosphere pressure. 

3. Use of a material such as a nitrous oxide- 
carbon dioxide mixture having a lower freezing 
point than that of carbon dioxide, thus per¬ 
mitting a larger amount of vaporization in the 
valve-manifold system before solid formation 
occurred. 

4. Use of mixtures of a noncondensable gas, 
such as air or nitrogen, with liquid carbon 
dioxide. This should give a greater initial dis¬ 
charge from equipment at low temperature. 

5. Redesign of the valve-manifold system in 
order to reduce the amount of vaporization 
occurring therein. 



34 


IMPROVED INFLATION OF LIFE RAFTS 


6 . Redesign of the cylinder dip pipe in order 
to secure liquid discharge regardless of cylinder 
position, thus ensuring vaporization in the raft 
rather than in the cylinder. 

7. Storage of life rafts in heated compart¬ 
ments so that they did not reach the low tem¬ 
peratures of the air at high altitudes. 

8 . Supply of heat to the cylinder by special 
means, such as burning powder or some other 
chemical reaction involving heat. 

s ' 41 Permanent Gas 

The use of a cylinder charged with com¬ 
pressed air gave the best inflation observed, but 
had the disadvantage that a larger and heavier 
cylinder was required. A Navy Mark I raft, 
equipped with a Mark IV cylinder containing 
compressed air, gave a 90 per cent inflation in 
15 sec with the raft initially at —40 F. The 
normal cylinder for this raft weighed 3.3 
pounds and contained 1.3 additional pounds of 
carbon dioxide; the larger air cylinder weighed 
7.2 pounds and contained 0.87 additional 
pound of air. This added weight was consid¬ 
ered too great a handicap. 

5 42 Nitrous Oxide 

Nitrous oxide (N 2 0), substituted for the car¬ 
bon dioxide in equal weight, gave the same vol¬ 
ume of gas. When this gas was discharged from 
a cylinder with the valve up (gaseous dis¬ 
charge), the results were no better than with 
carbon dioxide. A large portion of the material 
remained as a liquid in the cylinder, cooled to 
its boiling point at atmospheric pressure. With 
the valve of the cylinder down (liquid dis¬ 
charge), no plugging of valve or manifold 
occurred because no solid was formed. The 
cylinder was completely emptied in a maximum 
of 13 sec. Unvaporized liquid, however, was 
deposited in the manifold and raft, so that the 
degree of inflation of the raft in 1 minute was 
not appreciably better than with gaseous dis¬ 
charge of carbon dioxide. However, heat trans¬ 
fer to a liquid (nitrous oxide) is much greater 
than to a solid (carbon dioxide), and this ad¬ 
vantage was further increased by the greater 


area covered with the material in the raft 
rather than in the cylinder. As a result, the 
raft, originally at —40 F, was 100 per cent 
inflated in air in about 6 minutes. 


5 4,3 Mixtures of Nitrous Oxide and 
Carbon Dioxide 

Mixtures of nitrous oxide and carbon dioxide 
ranging from 6 to 83 per cent nitrous oxide 
were tested. The results obtained were no bet¬ 
ter than for carbon dioxide alone, when gaseous 
discharge was used. With liquid discharge, 
however, there was no plugging of the system 
with solid if 13 per cent, or higher, nitrous 
oxide was used. 


s- 4 - 4 Mixtures of Permanent Gas and 
Carbon Dioxide 

The addition of nitrogen to the standard car¬ 
bon dioxide charge in sufficient quantity to in¬ 
crease the pressure by 400 to 800 psi gave 
better results than the addition of nitrous 
oxide. Gaseous discharge was faster than for 
carbon dioxide alone, although about 40 per 
cent was left as solid in the cylinder, as with 
carbon dioxide alone. No plugging occurred 
during liquid discharge. 

5 45 Redesign of Valve Manifold System 

In the standard inflation system the carbon 
dioxide passed from the cylinder through a 
valve into a distributor, from which it passed 
through eight %- in. holes into the raft. These 
holes were large enough so that considerable 
expansion, resulting in vaporization, took place 
in the manifold, with consequent solidification 
of part of the liquid. If vaporization occurred 
in the valve manifold system, the resulting solid 
usually plugged the valve or manifold and pre¬ 
vented the discharge of the cylinder until 
enough heat was transferred to the plugging 
solid to vaporize it. The amount of vaporization 
occurring in the valve manifold system was de¬ 
termined by the relative dimensions of the pas¬ 
sages. Thus, if a small passage in the system 



PROPOSED MODIFICATIONS 


35 


was followed by a larger opening, the material 
flowing had to have a larger specific volume at 
the second point, since the weight passing the 
two points was necessarily equal. This larger 
specific volume was obtained by vaporization. 
If the heat necessary for the vaporization was 
not available from the sensible heat of the 
liquid carbon dioxide, solid formation occurred 
with probable plugging. By reducing the size 
of the distributor openings, the expansion in 
the distributor was reduced and the solid 
formation and plugging eliminated or ma¬ 
terially reduced. 

With the standard system, liquid carbon 
dioxide, if at a low temperature, could not be 
discharged from the cylinder because of plug¬ 
ging. Using i / 16 -in. holes in place of the 14 -in. 
holes, the cylinder contents were discharged 
through the manifold as a liquid in 20 sec. 
Solid carbon dioxide formed in the raft, how¬ 
ever, and inflation was not complete until this 
solid was vaporized. A Navy 4-man raft was 
tested with this modified distributor, with the 
raft cooled to — 53 F and inflated in water at 
38 F, using a liquid discharge. The raft was 40 
per cent inflated in one minute, 80 per cent in 
7 minutes, and 98 per cent in 14 minutes. Al¬ 
though this result was considerably better than 
would have been obtained with the standard 
distributor, it was not satisfactory. 

Distribution of carbon dioxide or nitrous 
oxide inside the raft was improved by replac¬ 
ing the metal distributor caps with long flex¬ 
ible tubes containing a large number of prop¬ 
erly distributed small holes. Using these tubes, 
80 per cent inflation was obtained with carbon 
dioxide or nitrous oxide in air in less than three 
min or in cold water in 45 sec. These tubes, 
however, add weight and might crack with con¬ 
tinued use or might burst when operated at 
high temperature. 


0 46 Redesign of Cylinder Dip Pipe 

In operation of standard inflation equip¬ 
ment, either gas or liquid discharge could be 
obtained depending on the position of the cyl¬ 
inder. As has been explained, liquid discharge 
produces much better results than gas dis¬ 


charge with either carbon dioxide or nitrous 
oxide. In order to ensure a rapid emptying of 
the cylinder with the valve end either up or 
down, an improved dip pipe was designed (Fig- 



Figure 1. Improved dip pipe for gas bottle used to 
inflate life-rafts. 

ure 1). This consisted of a rigid pipe B extend¬ 
ing from the valve end of the bottle to a point 
near the opposite end. A flexible weighted tip 
C was attached to the open end of the rigid pipe 












































36 


IMPROVED INFLATION OF LIFE RAFTS 


and 1 or 2 holes D were drilled in the wall of 
the rigid part of the dip pipe near the valve end 
of the bottle. Using this dip pipe with the valve 
end of the cylinder down, liquid flowed from 
the cylinder through the holes D near the valve 
end. With the valve end up, the liquid was 
forced through the holes in the weighted tip 
by the gas pressure above the liquid. 

With this improved dip pipe, results with 
nitrous oxide were very much improved. At 
least 95 per cent of the material was discharged 
into the raft within 30 sec regardless of 
whether the valve was up or down. Results 
with carbon dioxide were not as successful. 
Enough vaporization still occurred to convert 
up to 60 per cent of the material to solid, which 
remained in the cylinder or manifold. 


547 Storage in Heated Compartments 

Heating of the compartment of the plane in 
which the rafts were stored had been consid¬ 
ered by the Army and turned down because the 


electrical system was already overtaxed and 
heat by engine exhaust gases was not consid¬ 
ered safe on account of the danger of carbon 
monoxide entering the crew’s compartment as a 
result of leaks. 


5 48 Supply of Chemical Heat to Cylinder 

It would probably be possible to supply heat 
to the cylinder at the time of inflation by burn¬ 
ing gunpowder or by other chemical reaction. 
Inflation could also probably be obtained by the 
products of combustion of burning powder or 
by gas generated by chemical reaction, such as 
metal hydride and water. These systems, how¬ 
ever, would involve complete redesign of the 
inflation equipment and would not have been 
applicable to the thousands of units already in 
use, and for this reason they were not in¬ 
vestigated. 

The development of a chemically heated car¬ 
bon dioxide or nitrous oxide cylinder would be 
a logical subject of a future investigation. 


L 



Chapter 6 

ADVANCED POSITION IDENTIFICATION 


61 SUMMARY 

A s A temporary marker for advanced posi- 
- tions in the jungle, a paste was developed 
which would change from white to leaf green in 
about 1 hour. The composition was based on the 
use of barium sulfate as a pigment plus the dye 
Green AB in the stabilized leuco form. Al¬ 
though this material seemed suitable for dis¬ 
tribution from a small airplane, the amount 
needed was more than the limit of about 2 
pounds stipulated for use by ground troops. 

62 INTRODUCTION 

In combat operations, there was frequent 
difficulty in knowing where the front lines were 
with sufficient accuracy for direction of artil¬ 
lery fire and bombing from airplanes. This was 
particularly true in jungle operations where 
colored cloths laid down by the ground troops 
could not be seen from the air and where smoke 
signals did not rise straight up, but diffused 
through the trees, making the source difficult 
to estimate. Even in open country, smoke drifts 
too much in any wind, and both smoke and 
flares have too short a life to be sure that they 
will not be gone before they are sighted. Many 
casualties were inflicted on our own men be¬ 
cause of inability to tell exactly where they 
were. 

63 VANISHING MARKERS 

A possible solution to this problem was a ma¬ 
terial which could be used for marking the 
foliage and would disappear after a short time 
(% to 11/2 hours). It was thought that such a 
marker could be placed on the foliage by the 
ground troops with existing munitions, such as 
mortars or rifle grenades set to burst above 
treetop level, or that it could be sprayed onto 


the trees by a slow-flying observation-type 
plane. A plane of this type could pick up sig¬ 
nals from the ground where fast, high-flying 
planes could not. 

Previous work had shown that visibility de¬ 
pends more upon brightness contrast than upon 
color contrast. Since the reflectance of foliage 
is very low (about 10 per cent), a white or light 
color of high reflectance should produce the 
greatest visibility against a background of 
leaves. The color is of minor importance as long 
as the reflectance is high enough to give a large 
brightness contrast. 

Probably the best way to obtain the initial 
brightness would be to use a dye originally 
light-colored or colorless and depend on a pig¬ 
ment or substrate for the high reflectance. For 
best results the substrate should be an opaque 
white with good covering power. Barium sul¬ 
fate was used for this work, although it is pos¬ 
sible that better results could be obtained with 
one of the following: calcium carbonate, alu¬ 
mina hydrate, zinc oxide, magnesium carbonate, 
or titanium oxide. 

A liquid mixture for this purpose must be of 
a proper viscosity for efficient distribution, 
have a maximum stability of suspension, and 
maximum covering power. To obtain maximum 
covering power, it is necessary to use as large 
a solid-liquid ratio as possible. The proper vis¬ 
cosity depends upon the method of distribution 
and can be determined only by experiment. If 
the suspension is not stable at the solid-liquid 
ratio established by the preceding require¬ 
ments, it can probably be made so by the addi¬ 
tion of stabilizing materials. Six hundred 
grams of barium sulfate to 1 liter of liquid gave 
a stable suspension of not too high viscosity, 
and was used as the ratio in this investigation. 
The powdered barium sulfate was mixed with 
the liquid in a high-speed Eppenbach-Homorod 
mixer. In a column of this liquid 15 cm high, 
the barium sulfate showed no settling after 5 


37 


38 


ADVANCED POSITION IDENTIFICATION 


hours, had settled 0.2 cm after 24 hours, and 
0.2 cm after 336 hours. 

The process of changing the color of the 
paste by exposure to the air can depend upon 
oxidation. There was only one general class of 
dyestuff which had as the final step in its prepa¬ 
ration the oxidation of a substance (leuco 
form), which was colorless, or white, or lightly 
colored. This was the indigoid type of vat dye¬ 
stuffs which consisted of derivatives of indigo 
and thioindigo. The indigo derivatives may be 
blue, yellow, or green, and the thioindigo 
derivatives are generally red. Since the color¬ 
less or leuco form was easily oxidized and 
therefore quite unstable, a stabilized form 
(indigoid, solvat, algosol) of the leuco had been 
developed. The relationship between these three 
forms, stabilized leuco, leuco, and dye of this 
class of dyestuffs, is shown below for Green AB: 


Table 1. Time for the development of color of dyes with 
5.3-6.0 pH. 


Dye 

Vendor 

pH 

Time for 
color 
change 
(open 
shade on 
sunny day) 

Pink IREX 

Carbic Color and Chem¬ 
ical 

6.0 

8 min 

Pink R 

National Aniline 

5.7 

8 min 

Orange R 

National Aniline 

5.7 

8 min 

Yellow CG 

National Aniline 

5.7 

10 hr 

Yellow GK 

Carbic Color & Chem.; 
Gen’l Dyestuff 

6.0 

10 hr 

Green AB 

Carbic Color & Chem.; 
Gen’l Dyestuff 

5.5 

70 min 

Blue O 

National Aniline 

5.7 

25 min 

Blue 4B 

National Aniline 

5.5 

25 min 

Blue 6B 

National Aniline 

5.3 

20 min 

Blue 04B 

Carbic Color & Chem.; 
Gen’l Dyestuff 

5.6 

10 min 

Red violet RH 

National Aniline 

5.7 

8 min 



(X represents any halogen) 


Green AB 



It is apparent that for the stabilized form to 
be oxidized it must first be made acid. Acid 
must therefore be added to the paste composi¬ 
tions. 

Pastes were made of the available stabilized 
leuco forms of dyes, and tests made of the time 
for the change of color to take place after 
exposure to the atmosphere. The paste formula 
was: barium sulfate—60 grams, water—90 ml, 
6N sulfuric acid—10 ml, and stabilized leuco— 
1.5 grams. 

The paste was spread in a thin film on white 
paper and the time taken from the initial 
spreading until a color of medium strength had 
formed. This time was probably somewhat 
longer than it would take for the paste to be¬ 


come invisible from the air. The results are 
tabulated in Table 1. 

Green AB was the only pure dye found to 
give a color change within the required time 
limit. However, there was an indication that 
it might also be possible to develop a blend of 
one of the blue indigoid vat dyes and a yellow 
pigment or dye which would give a color 
change within the required time limits. 

All dyes of the triphenylmethane, methylene 
blue, and safranine groups are also capable of 
yielding leuco compounds. As in the case of the 
anthraquinone and sulfurized vat dyestuffs and 
in contrast to the indigoid vat dyestuffs, the 
leuco compounds of these dyes are generally 
somewhat colored. However, the leuco com- 


riAL 















VANISHING MARKERS 


39 


pounds of a few dyes in these other groups are 
colorless or lightly enough colored to be of use. 
An example of this in the triphenylmethane 
series is malachite green. There are undoubt¬ 
edly other examples. 

It was noticed that as the paste dried, the 
color change process was retarded and the 
final developed color was light and very spotty. 
To overcome this, sufficient glycerin was added 
to the paste to keep it moist for several hours 
of exposure. This added glycerin had no effect 
on suspension stability. A more uniform and 
complete color development was thus obtained. 
The weight ratio of glycerin to water required 
is between 15/85 and 30/70. A 30/70 ratio was 
recommended. In paste compositions a volume- 
for-volume replacement is made of water by 
glycerin-water solution. Triethanolamine and 
diethylene glycol were tried in place of glycerin. 
Although neither was as satisfactory as gly¬ 
cerin, diethylene glycol could be substituted if 
necessary. The formula recommended for use, 
therefore, was: 


Barium sulfate 

60 

g 

Water 

63 

ml 

Glycerin 

27 

ml 

6N Sulfuric acid 

10 

ml 

Stabilized leuco form of Green AB 

1.5 

g 


In order to estimate the contrast that this 
paste would have against a forest background, 
reflection measurements shown below were 
made of thin layers of the paste on a maple leaf 
background at different development times. 


Development Time of Paste 
(min) 

0 

15 

30 

45 

60 

75 

Green leaf background 


Reflectance (per cent) 

55 

42 

35 

20 

16 

11 

10 


The light source of the filter-type photo¬ 
electric spectrophotometer made by the Photo¬ 
volt Corporation gave a wavelength band of 
4,000 to 7,500 A and is designed to give a mea¬ 
sure of brightness. The pastes were exposed to 
direct sunlight between 10:00 and 11:00 a.m. 
EWT, in the month of October. After 75 
minutes, the reflectance contrast between the 
paste and the leaf green background is negli¬ 


gible. If the developed color of the paste is a 
close match for the leaf green, then the paste 
would be invisible even at close range. 

A rough determination of the covering power 
of these pastes was made by spraying with a 
compressed air-spray gun on a surface of 
pebbles and dirt on an asphalt roof. A uniform 
and continuous covering was obtained over an 
area of 45 sq ft with 800 ml of barium sulfate 
slurry made up in the ratio of 450 grams of 
barium sulfate to 1 liter of water. It is realized 
that the use of a spray gun resulted in a much 
more efficient distribution than can be ob¬ 
tained with any distributing mechanism used 
by the Services. Allowing a safety factor of 2 
and considering the facts that the paste used in 
the experiment contained 25 per cent less 
barium sulfate than any slurry previously 
studied (600 grams barium sulfate to 1 liter of 
liquid) and that there was an estimated 5 to 
10 per cent spray lost in the above experiment, 
it seems safe to assume that 1 quart, or 3.0 
pounds, of a paste containing 60 grams solids 
per 100 ml liquid will cover an area of 30 sq 
ft; 0.62 gallon, or 7.5 pounds, a circle 10 ft in 
diameter; and 2.5 gallons, or 30 pounds, a circle 
20 ft in diameter. 

These weights show that the paste-type 
marker would be too heavy for use by the infan¬ 
try. However, it was felt that the color-chang¬ 
ing paste discussed above might be usable by 
distribution from aircraft. No tests of dis¬ 
tribution from the air or visibility of the mark 
from the air were made. Pilots have stated that 
a white panel 10 ft in diameter can be easily 
seen from an altitude of 2,000 ft if its position 
is fairly well known beforehand. For use as a 
position marker it has been assumed that an 
area about 20 ft in diameter would be required. 

Powders involving the same type of color 
change were tried, but were unsuccessful be¬ 
cause of greater difficulty in obtaining adequate 
timing of the color change and because a dry 
powder did not stick to the foliage. Tests were 
made with deliquescent powders (calcium chlo¬ 
ride and lithium bromide), but it was found 
that the time required for the salt to pick up 
sufficient water to dissolve and disappear varied 
greatly with temperature, humidity, and par- 



40 


ADVANCED POSITION IDENTIFICATION 


tide size. This is shown in the following table 
giving results with calcium chloride. 


Particle size 

12 mesh 
20 mesh 
Fine crystallized 


Relative Humidity at 31 C 

30% 


150 min 
30 min 
9 to 10 min 


50% 

45 min 
20 min 
6 to 7 min 


90% 

30 min 
8 min 
4 to 5 min 


It is probable that the resulting concentrated 
salt solutions would kill the foliage and leave a 
permanent mark. 

Chemicals which would disappear by vola¬ 
tilization were investigated. Of all commer¬ 
cially available ammonium compounds only am¬ 
monium carbonate gave favorable results, and 
this material killed all foliage with which it 
came in contact within 24 hours. The organic 
chemicals tested were naphthalene, p-dichloro- 
benzene, and camphor, none of which were 
satisfactory. 


64 PARACHUTE MARKERS 

Any further work on this project should in¬ 
clude an investigation of the use of parachutes 
as markers. It is possible that they would be 
light enough to be carried by ground troops. 
There are two possible methods of providing 
for the disappearance of the parachute. One 


would be by impregnation with the leuco form 
of a green vat dye, so that the white parachute 
would turn to dull green in 1 to 2 hours. The 
other possibility would be the use of a highly 
inflammable paper, striped or crisscrossed with 
explosive material contained within waterproof 
tape, and having attached to it a time detonator 
to set off the explosive after a given time. If 
used by the ground forces, a projectile contain¬ 
ing the parachute could be shot into the air and 
at a predetermined height the parachute would 
be ejected from the case by a powder charge. 
The case could remain attached to the para¬ 
chute, acting as a weight to pull the parachute 
rapidly to the treetops. 

The weight needed per mark seems definitely 
to favor the parachute type of marker over the 
color-changing powder or paste. A smaller 
mark would be needed than with powder or 
paste because of the solid continuous nature of 
the mark obtained with a parachute as com¬ 
pared with a spotty mark from pastes or pow¬ 
ders. Calculations based on the weight of cur¬ 
rently used paper parachutes show that 1 pound 
of paper will give a mark 10 ft in diameter. 
Including the weight of the case and powder 
charges, a parachute marker projectile for a 
10-ft diameter mark might weigh 3 pounds 
and have an internal volume of about 3 pints. 



Chapter 7 

CHEMICALS FOR GENERATION OF HYDROGEN 


7.1 SUMMARY 

S everal chemical sources of hydrogen were 
investigated as possible improvements on 
the ferrosilicon-caustic system for filling mete¬ 
orological balloons. The addition of water to 
lithium hydride was known to be a convenient 
and efficient method, but lithium was very ex¬ 
pensive and in short supply. Accordingly, a 
method of making relatively cheap lithium was 
worked out. This involved calcining spodumene 
with high-calcium lime, leaching, settling, and 
decanting or filtering. The filtrate, containing 
finely divided calcium hydroxide, was treated 
with sulfur dioxide, filtered, and low-cost 
lithium hydroxide obtained by evaporating and 
drying of the filtrate. The lithium hydroxide 
was reduced at low pressure and at 1100 C by 
ferrosilicon in the presence of lime and lithium 
metal distilled off and recovered with high yield. 
The estimated cost of lithium hydride produced 
by this process was $3.00 per pound as com¬ 
pared with $12.00 per pound by the older elec¬ 
trolytic process. 

A briquetted mixture of sodium hydride and 
aluminum was developed as a much cheaper 
source of hydrogen. This material had many ad¬ 
vantages, although the volume of hydrogen per 
pound of chemical was only about 40 per cent 
of that from lithium hydride. Cheap and simple 
generators with the sodium hydride-aluminum 
mixture for field use were developed for inflat¬ 
ing small balloons. 

The possibilities of lithium and sodium boro- 
hydrides were investigated, but the manufac¬ 
ture of these materials appeared to be too com¬ 
plicated and expensive for the purpose. 

72 INTRODUCTION 1 

The Signal Corps employed the reaction of 
ferrosilicon and sodium hydroxide for the gen¬ 
eration of hydrogen in the field for filling me¬ 
teorological balloons. The generator used pro¬ 
duced the gas at 2,000 psi and was of heavy 


construction (450 pounds uncharged). The re¬ 
action of the chemicals was not complete; there¬ 
fore the charge of 9.5 pounds of solids produced 
only 80 to 90 cu ft of hydrogen. Besides the 
weights of equipment and chemicals, a further 
disadvantage was the difficulty of removing the 
residue from the generator after use; the 
sodium silicate residue solidified on cooling, and 
large amounts of hot water were required for 
cleaning. It was desired to obtain a generator 
for field use which was lighter in weight, easier 
to operate and which required the shipment of 
less generating chemical. 

A number of chemicals were considered, the 
more promising of which are listed below. 

Cu ft of 
Hydrogen from 
1 Pound of Chemical 


Ferrosilicon and caustic soda (actual) 9.5 

Sodium hydride (theoretical) 15. 

Sodium hydride and oil (actual) 16. 

Sodium hydride and aluminum (actual) 16. 

Calcium hydride (theoretical) 17. 

Calcium hydride commercial (actual) 7. 

Lithium hydride (actual) 42. 

Sodium borohydride (theoretical) 38. 

Sodium borohydride (actual) 16. 

Lithium borohydride (theoretical) 65. 


The listed chemicals, except ferrosilicon, de¬ 
pend only upon the addition of water for the 
production of hydrogen. 

Lithium hydride and ferrosilicon were the 
only materials commercially available. The 
lithium hydride was used on life rafts for pro¬ 
ducing hydrogen to fill balloons which carried 
up an antenna for an emergency radio trans¬ 
mitter. However, the available supply was not 
sufficient for meteorological balloons, and the 
price ($12.00 per pound) was considered too 
high for this use. The material was considered 
satisfactory from an operations standpoint. 

The NDRC investigation consisted primarily 
of two phases: the development of a new and 
cheaper method of producing lithium hydride, 
and the development of a method of manufac¬ 
turing a sodium hydride-aluminum mixture. 
The second phase included the design and pro- 


41 


42 


CHEMICALS FOR GENERATION OF HYDROGEN 


duction of experimental generators for use with 
the new hydride-aluminum mixture. 

7 3 PRODUCTION OF LITHIUM 3 8 

The method used for producing lithium metal 
was the electrolysis of fused lithium chloride. 
This was expensive because of the high cost of 
the electrolysis operation, the necessity of using 
a high purity salt, and the low concentration of 
lithium in the ores. The principal lithium ore 
is spodumene, a complex mineral composed 
principally of lithium-aluminum silicate, with 
varying amounts of sodium and potassium, and 
containing up to about 3 per cent lithium. 

The new process which was developed for 
lithium production depended on reduction under 
vacuum of lithium ores or salts and separation 
of the metal by distillation. Ferrosilicon was 
used as the reducing agent. Results indicated 
that the metal, or hydride, could be produced at 
one-third or less of the cost by the electrolytic 
method. 

Lithium has a remarkable affinity for oxygen 
and, at higher temperatures, for other gases 
such as carbon dioxide, carbon monoxide, nitro¬ 
gen, hydrogen, and water vapor. Because of the 
rarity and high cost of the inert gases, such as 
argon and helium, the best means for the exclu¬ 
sion of reactive furnace gases is by vacuum. 
The use of vacuum also permits the distillation 
of lithium from the reaction charge in a fairly 
pure state, and the removal of lithium from the 
reacting charge drives the reaction in the de¬ 
sired direction. 

The production of lithium was attempted by 
reduction of spodumene and of the three prin¬ 
cipal lithium salts, the chloride, carbonate, and 
hydroxide. The reducing agents investigated 
were ferrosilicon and finely divided metallic 
aluminum, finely divided metallic magnesium, 
finely divided metallic iron, and calcium car¬ 
bide. Ferrosilicon was found to be the most 
efficient. 

It was not possible to produce lithium by 
vacuum thermal reduction of the chloride be¬ 
cause of the high vapor pressure of this salt; 
the chloride volatilized out of the reaction zone 
before reduction could take place. Lithium 
could be produced from the carbonate using 


ferrosilicon and lime, but this reaction had 
several disadvantages. The carbon dioxide and 
carbon monoxide formed required the addi¬ 
tional pumping of 2,000 cu ft of gas per pound 
of lithium at a pressure of 10 mm. Also, the 
reduction of the carbonate formed some lithium 
carbide which contaminated the product, reduc¬ 
ing the purity to 80 per cent and causing the 
product to be pyrophoric. Lithium was pro¬ 
duced satisfactorily by reduction of spodumene 
with ferrosilicon in the presence of lime, but 
the concentration of lithium in the charge was 
only 0.9 per cent, necessitating the handling of 
large quantities of material in the vacuum 
retorts. The hydroxide gave the best results. 
Because of the high cost of the commercially 
available lithium hydroxide, which was pro¬ 
duced from the chloride, a process was de¬ 
veloped for obtaining the hydroxide directly 
from spodumene. 

The process finally recommended was as fol¬ 
lows : a mixture of 30 per cent spodumene and 
70 per cent high-calcium burned lime was cal¬ 
cined at 1050 C for 1 hour. The calcined ma¬ 
terial was leached with water just under 100 C, 
the slurry was settled, and the liquid decanted. 
Besides lithium hydroxide, the liquid contained 
a large quantity of lime, slaked during the 
leaching to produce a milk of lime suspension 
that was not amenable to thickening and filter¬ 
ing treatment by ordinary means. By treating 
this suspension with sulfur dioxide gas to the 
extent of 7 per cent of the amount necessary to 
react with the lime, a slurry was produced 
which did not settle readily, but which could be 
easily filtered. This enabled easy separation of 
the lithium hydroxide solution from the calcium 
hydroxide. Evaporation of the solution and 
drying the solid resulted in a low-cost lithium 
hydroxide suitable for vacuum thermal reduc¬ 
tion. The yield of lithium hydroxide from the 
spodumene was about 80 per cent. 

The lithium hydroxide was briquetted with 
ferrosilicon and lime in the proportions IFeSi 
(80 per cent Si) :2.7LiOH: 4CaO and heated to 
1100 C at a pressure of 1 to 25 microns. The 
reaction was probably as follows: 

24LiOH -> 12LLO + 12HX) 

12LLO + FeSi 6 + 15CaO 
-> 24Li + 3Ca 3 Si0 5 • 3Ca 2 Si0 4 + Fe 



SODIUM HYDRIDE-ALUMINUM MIXTURES 


43 


The lime was necessary to prevent the forma¬ 
tion of lithium silicate, which reduced the yield 
to about 40 per cent. With lime the yield was 
85 per cent to 90 per cent, or an overall yield of 
metal from the ore of about 70 per cent. Redis¬ 
tillation of the metal resulted in a product 
above 99 per cent purity. Based on a produc¬ 
tion of 2,000 pounds of lithium metal a day, it 
was estimated that the cost (without profit) 
would be about $3.00 a pound. The cost of the 
hydride would be little, if any, higher than that 
of the metal. 

About the time this process was developed 
the demand for lithium for sea-rescue kits fell 
off, and the production became available for 
meteorological use. Even though the produc¬ 
tion cost by the new process was much less, 
materials for new plants could not be made 
available as long as the existing electrolytic 
plants could meet the demand. 


74 SODIUM HYDRIDE-ALUMINUM 
MIXTURES 4 5 6 7 9 

An investigation of sodium hydride as a ma¬ 
terial for generating hydrogen disclosed that 
the pure material was unsatisfactory for field 
use because of its extreme reactivity. It is a 
fluffy powder which ignites spontaneously when 
exposed to air. Even when pelleted, its reaction 
with water was too violent to control. It was 
found that the addition of 25 per cent oil re¬ 
sulted in a product the reaction of which could 
be controlled, but the gas produced per pound 
dropped accordingly, and the oil was difficult to 
clean from the equipment and was also car¬ 
ried into the balloon by entrainment, necessi¬ 
tating the use of a filter. 

The substitution of granular aluminum for 
the oil gave a product even more stable than 
the oil mixture, but which produced as much 
hydrogen per pound as the pure hydride. The 
aluminum had the further advantage of neu¬ 
tralizing the caustic soda formed, so that the 
water solution of the residue was not hazardous 
to handle. A mixture containing 50 per cent 
aluminum (200 to 300 mesh) gave the best re¬ 
sults. Grade 3 secondary aluminum (93 to 94 
per cent purity) was used satisfactorily. 


Sodium hydride was produced by the hydro¬ 
genation of sodium according to the following 
equation: 

2Na + H 2 -> 2NaH + 28,000 calories 
The sodium was hydrogenated in the presence 
of the aluminum powder which served as a dis¬ 
persing agent for the sodium and resulted in an 
intimate mixture of the aluminum and sodium 
hydride in the final product. It was found that 
magnesium stearate increased the speed of 
hydrogenation and also acted as a binder for 
the pelleting. The amount of stearate required 
was approximately 0.12 per cent based on the 
final product. The reaction was carried out 
in a jacketed autoclave, equipped with an agi¬ 
tator, and connected to a Dowtherm circulat¬ 
ing system for heating or cooling the contents. 
The sodium was hydrogenated with hydrogen 
at 10 to 15 pounds pressure and with the re¬ 
actor contents maintained at 250 to 300 C. 

After heating to the desired temperature, 
cooling was necessary to remove the heat of 
reaction and to maintain the temperature at 
this point. When the reaction was completed, 
only about 20 percent of the product was with¬ 
drawn; the remainder was left for dispersion 
of the new charge. The material discharged 
was cooled, pelleted, and packaged in an inert 
atmosphere to prevent reaction with oxygen 
and moisture in the air. A 30-gallon autoclave 
produced approximately 4i/ 2 pounds of product 
per hour. 

Using secondary aluminum, the composition 
of the final product was approximately as listed 
below. 

Sodium hydride 50% 

Aluminum 46% 

Inerts (chiefly metallic impurities present in the 

aluminum) 4% 

This mixture reacted with water as follows: 

1.25NaH + 1.00A1 + Inerts + 2.25H 2 0 

(0.50 lb) (0.46 lb) (0.04 lb) (0.682 lb) 

-> 1.00NaA10 2 + 2.75H 2 + 0.25NaOH + Inerts 
(1.397 lb) (16.63 cu ft) (0.151 lb) (0.04 lb) 

Thus 1 pound of mixture will theoretically 
produce 16.63 cu ft STP of hydrogen. Ap¬ 
proximately 220 Btu is evolved for each cubic 
foot of hydrogen produced. 

A generator was developed to meet the de- 



44 


CHEMICALS FOR GENERATION OF HYDROGEN 


mands of the Signal Corps for filling their 
meteorological balloons, using the sodium hy¬ 
dride-aluminum mixture. The balloons used 
had capacities of 6, 25, and 70 cu ft. The gen¬ 
erator recommended (Figure 1) consisted of 
two parts: a cartridge (made in two sizes) 


GENERATOR ASSEMBLY 

LEGEND 

O - GAS OUTLET TUBE 
B - THREAD FOR ATTACHING 
GAS OUTLET TUBE 
C-IOO - CHARGE CONTAINER 
WITH CHEMICALS FOR 
100 GRAM BALLOON 
D- DUPLEX TYPE 

INTERRUPTED THREAD 
G - GENERATOR BODY 
J- INTERNAL CYLINDRICAL 
BELL 

P- PERFORATED SUPPORT 
PLATE 


Figure 1. Generator assembly designed for the 
chemical generation of hydrogen to fill meteoro¬ 
logical balloons. 

containing the proper amount of sodium hy¬ 
dride-aluminum mixture to fill the 6- and 25-cu 
ft balloons, and a scrubber which cooled and 
washed the gas. The cartridges were designed 
to be discarded after use whereas the scrubber 
was designed for reuse with cartridges of either 
size. 

The scrubber was cylindrical in shape and 
weighed about 2.8 pounds. It was 16 in. high 
and 6 1/2 in. in diameter. An internal cylindri¬ 
cal bell 4 14 in. in diameter was attached in 
the bottom half of the outer cylinder. The 
scrubber was open at the bottom and was 
closed at the top, except for a gas outlet tube. 
The 6-cu ft cartridge was 21/2 in. high by 3% 
in. in diameter and weighed 0.8 pound includ¬ 
ing 0.4 pound of charge. The 25-cu ft cartridge 
was 714 in. high by 3% in. in diameter and 
weighed 2.3 pounds, including 1.5 pounds of 
charge. For filling the cartridges the hydride 
aluminum was compressed into pellets 2% in. 
in diameter and % to 1 in. thick. 

In operation, a pull tab was removed from 



the bottom of the cartridge exposing a V^-in. 
diameter hole, and a friction cover was re¬ 
moved from the top exposing a series of !% 4 -in. 
holes. The cartridge was then attached inside 
the cylindrical bell of the scrubber by means of 
a quarter-turn coupling. The generator assem¬ 
bly was immersed in water to within 1 in. of 
the top. Water entered the cartridge through 
the hole at the bottom and reacted with the 
chemical. The hydrogen generated was emitted 
from the cartridge through the holes at the 
top, was deflected downward by the internal 
cylindrical bell, and passed under the saw- 



Figure 2. Operation of chemical hydrogen gen¬ 
erator. 


toothed edge of the bell. The gas then flowed 
upward through the water in the space between 
the bell and the outer wall of the scrubber, 
disengaged from the water surface in the space 
above the bell, and passed through a hose to 
the balloon. In passing through the water the 
gas was washed and cooled. The small cart- 





























INVESTIGATION OF OTHER CHEMICALS 


45 


ridge produced hydrogen at the rate of ap¬ 
proximately 1 % cfm and the larger cartridge 
at the rate of approximately 2 % cfm. Large 
balloons could be filled by discharging three 
large cartridges consecutively or in series. 



Figure 3. Operation of chemical hydrogen gen¬ 
erator to inflate balloon. 


Figures 2 and 3 illustrate the operation of the 
generator by immersion in water contained in 
an open drum. 

The following table gives data on the rise in 
alkalinity and temperature of the water which 
was used for four consecutive generators of 
25-cu ft charges of sodium hydride-aluminum 
mixture. The data are based on the use of 250 
pounds of water, originally at 63 F. 



Wt Chem¬ 

Final 

Maximum 


Generator 

ical Used 

Water 

Gas 

Free 

Number 

(Grams) 

Temp F 

Temp F 

NaOH 

1 

789 

92 

101 

0.12% 

2 

782 

120 

126 

0.24% 

3 

790 

147 

174 

0.36% 

4 

790 

165 

189 

0.48% 


75 INVESTIGATION OF OTHER 
CHEMICALS 2 

Pure calcium hydride was produced for the 
British by hydrogenation of calcium metal. 
This material was satisfactory, but because 
electric furnaces were required in producing 
the metal, it was expensive and the supply 
limited. 

A process was available for producing an 
impure calcium hydride by the reduction of 
lime with aluminum or magnesium according 
to the following reactions: 

3CaO + 2A1 + 3H 2 -> 3CaH 2 + A1 2 0 3 
CaO + Mg + H 2 -> CaH 2 + MgO 

The hydride produced in this way is only about 
40 per cent pure. However, it reacts with water 
satisfactorily to produce hydrogen. 

Because of the large volume of hydrogen 
theoretically produced from a unit weight of 
sodium borohydride, an investigation was made 
of the practicability of producing it. Because 
of the high cost of lithium, the lithium boro¬ 
hydride was not considered feasible. Two pos¬ 
sible methods for producing sodium borohy¬ 
dride were considered. 


7.5.1 First Process 

1. Preparation of sodium trimethoxy borohydride. 

a. 2Na + H 2 -> 2NaH. 

b. 3CH 3 0H + B 2 0 3 -> (CH 3 0) 3 B + H 3 B0 3 . 

c. NaH + (CH 3 0) 3 B -> NaBH(OCH 3 ) 3 . 

2. Preparation of diborane. 

a. 6NaBF 4 -f- B 2 0 3 -p 6H 2 S0 4 ^ 8BF 3 -f- 

6NaHS0 4 + 3H 2 0. 

b. BF 3 + (C 2 H 5 ) 2 0 -> BF 3 -(C 2 H 6 ) 2 0. 

c. 6NaH + 8BF 3 -(C 2 H 5 ) 2 0 -> B 2 H 6 + 

8(C 2 H 5 ) 2 0 + 6NaBF 4 . 

3. Preparation of sodium borohydride. 

a. 2NaBH(OCH 3 ) 3 + B 2 H 6 -> 2NaBH 4 + 
2(CH 3 0) 3 B. 

7.5.2 Second Process 

1. Preparation of sodium trimethoxy boro¬ 
hydride, as above. 

2 . Preparation of sodium borohydride. 

4NaBH(OCH 3 ) 3 ^ NaBH 4 + 3NaOCH 3 + 

3(CH 3 0) 3 B. 







46 


CHEMICALS FOR GENERATION OF HYDROGEN 


In the second process the borohydride must be 
separated from the final mixture by dissolving 
it in pyridine or liquid ammonia, filtering and 
evaporating off the solvent. 

A preliminary engineering study indicated 
that both processes were too complicated for 
the borohydride to compete with the sodium 
hydride-aluminum mixture on a cost basis. In 
each case the starting point was NaH as was 
used directly in the sodium hydride-aluminum 
mixture. 

Further work by the Army Signal Corps dis¬ 


closed that pure sodium borohydride was not 
sufficiently reactive with water for field gen¬ 
eration of hydrogen. In order to correct this, 
it was necessary to add an acidic material, 
such as boric oxide, and this reduced the amount 
of hydrogen produced per pound of material. 
The borohydride has the advantage of being 
less pyrophoric than most of the others con¬ 
sidered, and is therefore safer to handle in 
case of accidental breakage of the containers. 
Sodium hydride is poorest from this stand¬ 
point. 



Chapter 8 

PLANE CRASH DYE MARKER 


si SUMMARY 

A S an AID IN SEA rescue work a dye marker 
was developed which was ejected auto¬ 
matically as the airplane hit the sea. The 
ejection was accomplished by squibs actuated 
electrically through a switch which was closed 
by sea water. The floating container carried 
uranine dye compounded with polyvinyl alcohol 
to control and extend the time of solution of 
the dye in sea water. The mark produced was 
visible from 5 to 8 miles at 10,000 ft and per¬ 
sisted for 16 hours. 


82 INTRODUCTION 

Search parties looking for survivors of a 
plane crash at sea had a very difficult task 
unless there was some way of knowing the 
approximate location. A dye marker had been 
proven an effective aid for attracting planes, 
and was carried in life jackets and as part of 
the equipment in all life rafts. The dye used 
was powdered uranine, the soluble sodium salt 
of fluorescein. The dye was released by the 
survivor when a plane was sighted, producing 
a brilliant yellow fluorescent patch on the 
water. This mark lasted for 1/2 to 1 hour and 
if the plane did not see it, no more dye was 
available. Occasionally the survivors in the 
rafts were unconscious and unable to release 
the dye or use other available signal devices. 

Because of this situation a project was un¬ 
dertaken for the development of a device which 
could be attached to a plane without impairing 
its performance, and which would be released 
automatically if the plane crashed in water, 
producing a mark visible for about 8 miles at 
an altitude of 10,000 ft and lasting a minimum 
of 16 hours. The weight of the unit had to be 
small enough so that it could be carried on any 
type of plane. 


8 3 DYE composition 

Considerable previous work had indicated 
that uranine was as effective a marking ma¬ 
terial as could be found, but when used as an 
unconfined powder the mark was soon dissi¬ 
pated by motion of the water. It was decided, 
therefore, to use uranine rather than to search 
for a better material, but to devise some method 
of controlling the solution of the dye. 

Experiments showed that from 0.3 to 0.4 
pound of dye per hour, released continuously, 
was required for a mark having the desired 
visibility. Attempts were made to control the 
solution to the desired rate by enclosing the 
dye in a cloth bag, but the untreated dye still 
dissolved too fast. A coating of stearic acid 
on the dye retarded the rate of solution too 
much. All the rates obtained with this bag 
method, however, varied more with varying 
intensity of wave action than could be toler¬ 
ated. Following these tests the bag method 
was discarded and the use of a solid cake of 
uranine decided upon. 

A number of water-soluble binding agents 
were tried and several were satisfactory. The 
mixture recommended was: 

Uranine (Calco 86% or equivalent) 87.5% 

Polyvinyl alcohol (high viscosity) 1.0% 

Water 11.5% 

The polyvinyl alcohol was dissolved in the 
water and mixed with the uranine in a heated 
dough mixer until a uniform dough was ob¬ 
tained. The mixture was then pressed into the 
two open ends of a 4-in. aluminum tube having 
an air space in the center of the tube to give 
the cylinder buoyancy. Methyl cellulose and 
Cellosize were as effective as polyvinyl alcohol 
as binders. The inclusion of a binder was nec¬ 
essary to prevent a “honeycombing” effect as 
the dye dissolved. It was later determined that 
somewhat better results were obtained by mix¬ 
ing uranine with 3 or 4 per cent of water and 
1 or 2 per cent of binding agent and pressing 
it under 6 to 8 tons per sq in. 



47 


48 


PLANE CRASH DYE MARKER 


Trials of this dye-filled cylinder indicated 
that the rate of solution was about right at 
the start, but that less dye was needed to re¬ 
plenish that which dissipated after the mark 
was established. The cylinder as finally de¬ 
signed (Figure 1) was 4 in. in diameter and 
16 in. long. The dye compartments (one in 
each end) were in the shape of a frustum of 



Figure 1. Dye-filled cylinder serving as sea 
rescue marker. 


a cone, 4 in. in diameter at the large end, 1 % 
in. in diameter at the other end, and 8 in. long. 
The 4-in. ends were welded to the open ends 
of the cylinder, leaving an air chamber around 
the dye containers. As the dye dissolved, a con¬ 
tinually reduced surface was presented to the 
water. Sea trials showed that this unit, which 
contained 6 pounds of dye mix, gave a satis¬ 
factory mark for 16 to 18 hours. 


84 RELEASING MECHANISM 

The releasing mechanism designed for auto¬ 
matic ejection of the dye was actuated by a 
water switch which was closed by sea water 
when submerged. Two dry-cell batteries deto¬ 
nated three electric squibs, which blew off the 
catches. Two springs ejected the dye container. 
The unit was designed to be mounted inside 


the plane’s surface, with the panel through 
which the dye was ejected mounted flush with, 
and acting as part of, the skin of the plane. 
Suitable traps were placed between the water 
switch and the entrance for the water so as 
to avoid any possibility of premature opera¬ 
tion due to rain or splashing of water. Trials 
showed that the release mechanism was ac¬ 
tivated within 7 sec of contact with water. 
The complete model weighed approximately 9 
pounds. 

A second unit was developed for mounting 
externally. On planes where a slight added 
air resistance could be tolerated, this unit had 
the advantages of simpler design, easier instal¬ 
lation, and of being mountable on any type 
of plane without modification. The operating 
and releasing principles were the same as for 
the internally mounted model. The design con¬ 
sisted of a teardrop-shaped shell 17% in. long 
and 6% in. at its largest diameter. The for¬ 
ward section was sealed off as a buoyancy 
chamber and the rear section filled with 6 
pounds of dye cake. Between these two sec¬ 
tions was the releasing mechanism previously 
described. The shell was fastened to a base 
plate permanently attached to the plane. The 
squib released the shell from the base plate 
exposing an opening to the dye chamber. 

The shape of the dye container of this model, 
as well as the location, shape, and size of the 
area of dye exposed to the water, differed 
markedly from that of the internally mounted 
design. This would in all probability require 
a different dye composition. No tests at sea 
were made with this unit and the necessary 
modifications in the dye composition were not 
worked out. 










Chapter 9 

DEVELOPMENT OF OXYGEN MASKS 


91 SUMMARY 

A s A result of a study made in the fall of 
- 1940, it was evident that the oxygen masks 
then in use were not usable at high altitudes 
and low temperatures. A new molded rubber 
mask was designed and tested, and shown to 
be satisfactory in all important respects. This 
mask represented a very great advance in its 
ability to operate at very low temperatures, 
and was adopted and procured in quantity as 
the Army A-9 mask immediately after Pearl 
Harbor. 

A subsequent requirement of a full head cov¬ 
erage mask was met by a development involv¬ 
ing an eye and an oro-nasal cavity with a check 
valve between, arranged so that the fresh air 
or oxygen was first drawn over the double plas¬ 
tic eyepieces. This mask operated satisfactorily 
without fogging of the eyepieces at —50 F. 

92 INTRODUCTION 

Before the start of World War II it was 
realized that the oxygen mask then in use was 
not satisfactory for extended periods at the 
high altitudes and low temperatures. A study 
of the problem indicated that the following 
points should be considered in constructing an 
oxygen mask: 

1. Comfort. 

2. Interference with vision. 

3. Mask dead space. 

4. Marginal leakage. 

5. Effects of cold. 

6 . Arrangements for microphone. 

7. Nonirritation of face in heat and cold. 

8 . Mask suspension—ability to loosen with 
one hand. 

9. Resistance to breathing. 

10. Characteristics and quality of mask rub¬ 
ber. 

11. Location of oxygen ports and exhalation 
valve. 

12. Oxygen supply regulator. 


Before the development of a new mask was 
started, the efficiencies of the three military 
masks then in use were determined. The first 
of these masks was the MSA Type A mask 
(Navy White Long). This mask was long and 
narrow, made of rather inelastic rubber, and 
had a very narrow bearing surface upon the 
face. It required extremely tight strapping to 
be made even approximately tight. The mask 
was intended for use with the MSA self-con¬ 
tained oxygen apparatus. It contained no 
valves, and it was impossible to avoid leaks 
around the bridge of the nose and around the 
corners of the mouth, which were particularly 
prominent during talking. It was unsuitable 
for use with a closed-circuit oxygen apparatus 
and could not be used with any oxygen supply 
system where waste of oxygen was a matter 
of any moment. A leaky mask such as the Navy 
White Long can be employed only where oxy¬ 
gen is delivered to the mask under slight posi¬ 
tive pressure and a constant degree of outward 
leakage is expected. 

The second mask tested was MSA Type B 
mask (Navy White Short). This mask could 
be made quite tight if sufficient tension on the 
straps was used, but it was held to the face 
by the straps rather than being fitted to the 
face. Leakage was preventable, but leaks 
around the bridge of the nose frequently oc¬ 
curred. On testing in the low-pressure cham¬ 
ber, the mask was regarded as unsatisfactory, 
and would be very dangerous in the presence 
of severe cold since ice formation readily oc¬ 
curred inside the mask at subzero tempera¬ 
tures. 

The third mask tested was the BLB oro-nasal 
mask Type A-8. This mask used a disk of 
sponge rubber as the exhalation valve, and 
inspiration was accomplished by taking oxygen 
from a rubber bag pendant from the lowest 
part of the mask, the oxygen being supplied 
continuously to the bag by an automatic re¬ 
ducing valve. The mask was fragile, and the 
breathing bag very light. It could be made to 


49 


50 


DEVELOPMENT OF OXYGEN MASKS 


fit if strapped tightly, but was uncomfortable. 
If used under quiet circumstances at altitudes 
not above 17,000 ft in cabins warmed so as to 
prevent ice formation, the BLB oro-nasal mask 
was considered safe. In military aviation, 
where higher altitudes must be met and where 
subzero temperatures are regular, the mask 
proved unsuitable, the sponge-rubber exhala¬ 
tion valve freezing regularly and extensively 
so that practically no air could be forced 
through it. 

For testing these masks and the masks later 
developed, it was necessary to work out suit¬ 
able methods. The determination of points of 
mask leakage was made by means of the well- 
known coal-dust spray technique. Mask leak¬ 
age was also tested by a helmet technique dur¬ 
ing normal breathing, during increased breath¬ 
ing due to inhalation of increased C0 2 , and dur¬ 
ing continuous talking. 4 

In addition to the testing of the masks, the 
efficiency of the MSA self-contained oxygen 
apparatus was also determined. In this appa¬ 
ratus, which was for use with the MSA Type 
A mask, oxygen was generated chemically in a 
canister containing a compound which gave off 
oxygen. The carbon dioxide and water vapor 
were removed by the reaction which liberated 
oxygen. The apparatus was a closed-circuit 
device and was said to provide about 45 liters 
of oxygen for the small canisters supplied, and 
65 liters for the larger canisters. In such an 
appliance the subject breathes through the 
canister, and it is essential that no serious 
development of resistance occur during use. 
The principal defect of the appliance was the 
development of resistance frequently greater 
than 10 cm of water while the subject was at 
rest, and intolerably high during mild work. 
Owing to changes in resistance and difficulty 
of access of water vapor to the chemical in 
the canister, the oxygen supply provided by it 
was neither constant nor, at times, adequate. 
These defects were so pronounced at sea level 
and under normal room temperature that its 
performance was not tested at low tempera¬ 
tures or under conditions of low barometric 
pressures. 


93 DEVELOPMENT OF THE L-12 MASK 

With this background concerning the im¬ 
portant features of a satisfactory oxygen mask 
and the faults of the existing masks, a new 
mask, designated the L-12, was designed. Fig¬ 
ure 1 is an illustration of this mask. In order 



Figure 1. Three-quarter view of fully equipped 
L-12 oxygen mask. 

to prevent leakage of the mask, there was a 
large surface in contact with the face and the 
mask was carefully shaped around the nose 
and chin so that a tight fit was obtained with¬ 
out the necessity of tight strapping. There is 
no region where masks become more uncom¬ 
fortable than across the nasal bridge, if hard 
pulling is required to prevent leakage. A loop 
of wire is necessary for most wearers in order 
to assure absolute tightness about the nose. 
The ports for entrance of oxygen or oxygen 
mixtures were at a distance from the exhala¬ 
tion valve, so that the cold entering oxygen 
would not freeze the water vapor in the ex¬ 
haled air, with consequent plugging of the valve 
and obstruction to breathing. For the same 
reason, the exhalation valve was placed as 
near the mouth as possible in order to take 
advantage of the maximum warmth of the ex¬ 
pired air for the prevention of ice formation. 
In the presence of wind a shield was necessary 
to protect the expiratory valve to avoid ice 


C 




THE FULL-FACE OXYGEN MASK 


51 


formation in the exhaled air. This shield was 
molded from the same type of rubber used in 
the face piece, and was cemented on, being so 
formed as to fit exactly. There were no sur¬ 
face obstructions which interfered with vision, 
and there was no difficulty in wearing the 
Army goggles with the mask. The rubber used 
had had a long period of testing in Army gas 
masks and was known not to cause irritation 



Figure 2. Side view of A-9 oxygen mask without 
straps. 

or allergy. The dead space in the mask varies 
for different facial contours, but it rarely is 
above 100 cu cm. 

Leakage tests on the L-12 mask showed it to 
be satisfactory from this standpoint, and tests 
in the low-pressure chamber indicated that 
subjects at rest and light work received ade¬ 
quate oxygen through the mask at altitudes up 
to 40,000 ft and experienced no discomfort 
from the mask. The mask was outstanding in 
its ability to withstand extremely low tempera¬ 
tures for several hours. 

Field and laboratory work on this mask 
sponsored by the NDRC and the Army Air 
Forces resulted in changes in the suspension, 
in the method of securing a tight fit about the 
nose, and in the construction of the expiratory 


valve and oxygen inlet tube. After these 
changes had been incorporated, the mask was 
adopted by the Army as the A-9, and com¬ 
mercial production was begun in January 1942. 
This final mask is shown in Figure 2. The 
Army Air Forces later made modifications of 
the A-9 mask which resulted in the A-10 mask. 
Similar masks were later developed by the 
Mine Safety Appliance Company for the Navy 
and by the Canadians for the RCAF. 


94 THE FULL-FACE OXYGEN MASK 

These masks covered only the lower part of 
the face, and, when worn with goggles, left 
part of the face exposed. Occasionally freezing 
resulted from extended exposure to very low 
temperatures. To prevent this, a full-face oxy¬ 
gen mask was developed, with fogproof gog¬ 
gles incorporated so that the vision would be 
unobstructed by fog or frost at subzero tem¬ 
peratures. The principles upon which this de¬ 
velopment was based may be listed as follows. 

1. Separation of the mask into two compart¬ 
ments : one, the eye compartment, and the 
other the oro-nasal compartment. 

2. Controlled one-way ventilation of the eye 
compartment by the inhaled air of the wearer 
for the removal of the water vapor formed by 
the eyes and surrounding skin, which vapor 
would, by saturating the air over the eyes, 
cause lens fog. 

3. Exclusion of the saturated exhaled air 
from the eye compartment where the added 
water vapor arising from the lungs would in¬ 
tensify the formation of lens fog, the exclusion 
being accomplished by a valved connection be¬ 
tween the eye and oro-nasal compartments as 
well as by a nasal sealing ridge built into the 
mask between the two compartments. 

4. The use of a double plastic lens, embody¬ 
ing an air cell 0.060 in. thick, by means of 
which the outer and inner surfaces of the 
lenses are effectively insulated one from the 
other, thus greatly reducing the loss of heat 
from the eye compartment. 

5. The use of an absorbent (antifog) coat¬ 
ing on the surface of the lens nearest the eye 
to prevent the formation of intermittent fog 


C< 



52 


DEVELOPMENT OF OXYGEN MASKS 


during the exhalation period when at tempera¬ 
tures lower than 30 F. 

6 . The elimination of external clamps used 
for sealing the lenses in the mask, by making 
use of the elasticity of the rubber as well as 
building into the eyepieces flexible metal beads 
to prevent the accidental removal of the lenses. 

7. The shielding of the exhalation valve 
after the manner of the A-10 series of oxygen 
masks to prevent freezing of the expiratory 
valve, except that the shield was integrally 
molded with the face piece instead of being 
cemented. 

Without the aid of externally applied heat, 
the limit of usefulness of the mask was around 

— 50 F, though tests at Wright Field gave 
fairly satisfactory results at a temperature of 

— 91 F. The application of external heat by 
means of an electrical heater in the oxygen 
inlet tube theoretically allowed satisfactory use 
of the mask to any desired subzero tempera¬ 
ture. 

The lenses of the final mask were 2i% 6 in. 
in diameter. Perimeter tests on the visual 
fields, conducted by the Aeromedical Labora¬ 
tory, Wright Field, showed this mask to be 
better than the B-8 goggles. 

After a few changes proven necessary by 
field tests, three sizes of the mask were con- 



Figure 3. Front view of A-16 full-face oxygen 
mask showing large eyepieces, eye clamps, and 
the method of molding valve-shield as an in¬ 
tegral part of the mask. 

structed and were standardized by the Army 
as the A-16. This mask is shown in Figure 3. 


ODNFfDKN’tBtlr^ 




Chapter 10 

LEVINSTEIN-H 


101 SUMMARY 

M ustard gas produced by the standard 
Levinstein process is impure, relatively 
unstable, and has physical properties which 
are undesirable for many tactical uses. For 
these reasons methods were developed by 
which the Levinstein product (H) might be 
purified. Additives were developed to reduce 
the shatter of mustard when used as an air¬ 
craft vesicant spray and to produce a rain of 
controlled drop size. A great many data were 
obtained on the stability of the Levinstein 
product and of the thickened agent. Data on 
evaporation of drops and drag coefficients for 
falling drops were employed to determine the 
loss due to evaporation from aircraft spray. A 
new mixed agent involving the addition of 
small quantities of white phosphorus to mus¬ 
tard was partially developed. This showed re¬ 
markable promise for the rapid production of 
concentrations of mustard vapor high enough 
to be lethal to masked troops in a very short 
time. 

Laboratory and pilot plant studies showed 
the feasibility of purifying H by pentane dis¬ 
tillation, fractional melting, pentane extrac¬ 
tion, pentane detarring, steam distillation, or 

Table 1 . Gauge pressures (psi) developed during 
storage at 65 C in contact with iron. 


Number of days 
at 65 C 
20 40 60 


Crude Levinsteins (average of 18) 

17 



Steam distilled (brick semi-works) 

11 

17 

20 

Crude Levinstein plus 1 per cent 
hexamine 

7 

12 

20 

Thiodiglycol H, plus 1 per cent hex- 
amine 

3 

6 

9 

Pentane detarred, plus 0.2 per cent 
hexamine 

2 

5 


Steam distilled (laboratory glass 
column) plus 1 per cent hexamine 

1.5 

2 

3 

Steam distilled (ceramic column), 
no inhibitor 


2 

2.5 


vacuum distillation. Table 1 indicates the 
pressure stability of several of the products. 


Plant design estimates indicated steam distil¬ 
lation to be the simplest and cheapest process, 
and a joint report 21 by NDRC and the Chemical 
Warfare Service [CWS] Development Labora¬ 
tory (September 16, 1943) recommended the 
installation of purification plants using steam 
distillation. The subsequent development that 
unused Lewisite plants might be converted for 
H purification led to the installation of a 
vacuum distillation unit. 

Early work by the British showed that air¬ 
craft spray was most effective in producing 
casualties if the drops formed were in the 
range 1.5 to 5.0 mm diameter, and that the 
addition of chlorinated rubber and benzene to 
H led to the production of drops in this size 
range. In cooperation with CWS, groups work¬ 
ing under NDRC made a search of possible 
thickening agents and developed test tech¬ 
niques to supplement the field trials. The 
thickened H mixture developed and adopted 
contained 0.6 to 0.9 per cent polymethyl metha¬ 
crylate (scrap Lucite or Plexiglas), 1.7 per 
cent crude nitrogen bases, 12.7 to 12.4 per 
cent benzene, and 85 per cent H stabilized with 
1 per cent hexamethylene tetramine. This mix¬ 
ture gave the desired drop size distribution, 
due to the structure rather than the viscosity 
of the liquid. 

In connection with the several problems 
related to H, it was necessary to carry out 
numerous stability tests of H and H com¬ 
positions under various conditions. The thick¬ 
ened H mixture described above is stable in 
lined M47 bombs for 3 to 6 months at 65 C 
(149 F). 

In order to determine the amount of H 
which might evaporate in the use of high- 
altitude spray, data were collected on the 
evaporation of liquid drops and correlations 
obtained covering a wide range of conditions. 
The estimated evaporation of H in falling from 
10,000 ft at 20 C is estimated to be 1 per cent 
for 6-mm drops, 8 per cent for 2-mm drops, 


53 






54 


LEVINSTEIN-H 


28 per cent for 1-mm drops, and 100 per cent 
for 0.5-mm drops. 

It was found that the effective volatility of 
H might be greatly increased by incorporating 
2 to 4 per cent of white phosphorus. This 
oxidized on contact with air and the tempera¬ 
ture of the liquid H was raised more than 100 
C. The result was copious evolution of a dense 
H smoke. Best results were obtained by the 
use of 15 per cent cyclic ethylene trithiocar- 
bonate as a cosolvent, with the liquid held in 
the pores of small cubes of cellulose sponge. 
The development was not complete, as the 
sponge was not chemically stable in H, and 
the retention of the liquid by the sponges was 
rather low. The results indicated, however, 
that concentration-time dosages lethal to 
masked troops might be obtained in a very 
few minutes under conditions such that hours 
would be required with untreated H. 


io .2 INTRODUCTION 

Mustard gas, a powerful vesicant, was in¬ 
troduced as a chemical warfare agent by the 
Germans in 1917. In the early stages of World 
War II it became evident that this material 
would probably be the most important and 
widely used chemical agent if chemical war¬ 
fare should break out, and various important 
problems concerning its tactical use were 
presented. The U. S. production was based on 
the Levinstein process and the product H was 
an impure material with an undesirably high 
freezing point, about 50 F, containing 70 to 75 
per cent of the active agent, 6is-/?-chloroethyl 
sulfide. The large amount of impurities not 
only represented inactive diluent but resulted 
in poor storage stability at elevated tempera¬ 
tures, and presented serious obstacles to the 
development of new weapons and new formula¬ 
tions involving H. It is to be hoped that if H 
continues to be regarded as an important 
agent, the Levinstein process will be replaced 
by one of the alternative production methods 
by which pure H can be readily produced. 


103 PURIFICATION OF LEVINSTEIN-H 

1031 Introduction 

The importance of the stability of H on 
tropical storage and the necessity of developing 
a thickening agent for the anticipated use of 
high-altitude vesicant spray led to considera¬ 
tion in late 1942 of ways and means of obtain¬ 
ing pure mustard. Since U.S. production of H 
was based on the Levinstein process, it seemed 
more expeditious to develop methods of puri¬ 
fying the Levinstein product than to construct 
new plants for the manufacture of the pure 
agent. Accordingly, NDRC and CWS under¬ 
took simultaneously to develop and evaluate 
several processes for the separation of the pure 
mustard from the Levinstein product, of which 
large quantities were on hand. 


10 ’ 3 ’ 2 Pentane Distillation 

Because of the erroneous belief that hydrol¬ 
ysis of the H would be excessive if steam were 
employed, a study of vapor distillation using 
pentane vapor was initiated. The first equip¬ 
ment was of steel, and although coking was 
encountered in the packed towers, successful 
runs were made giving a product containing 
97 per cent mustard on a pentane-free basis. 27 
The steel equipment was redesigned with acid- 
proof brick lining in the towers and stainless 
steel piping, but the project was dropped be¬ 
fore additional data were obtained because of 
the success of parallel studies of purification 
by other methods. 


10 3 3 Fractional Melting 

Small-scale experiments indicated the con¬ 
siderable promise of a novel purification meth¬ 
od involving fractional melting. Solid H was 
partially melted and the two phases separated 
on a chilled vacuum filter. Although the effi¬ 
ciency of separation in a single step was not 
high, it seemed entirely practical to operate 
a multistage countercurrent system which 
would give high purity and good yield. Be- 



PURIFICATION OF LEVINSTEIN-H 


55 


cause of the success of the other processes, this 
method 22 was never carried to the pilot plant 
stage. 


10,3 4 Steam Distillation 

This method showed promise when tried on 
a laboratory scale in World War I, but was not 
developed at that time. Work by the CWS 
Development Laboratory in 1942 indicated the 
possible advantages of steam distillation, and 
both NDRC and CWS proceeded with the 
development of the process on a pilot plant 
scale. The first tests with stainless steel col¬ 
umns gave difficulties due to coke and tarry 
deposits; ceramic-lined packed towers were 
then substituted. As finally developed, the proc¬ 
ess 28 involved a short-time countercurrent con¬ 
tact of the crude H with superheated steam. 
The overhead vapors were condensed in a 
silver condenser, the water layer was discarded, 
and the mustard layer was dried, inhibited 
with hexamethylene tetramine, and stored in 
steel drums. The residue from the bottom of 
the column was discarded. No difficulty was 
encountered in operating the steam-distillation 
column for extended periods. Thus in a run 
for 146 hours with crude H from several lots, 
57 pounds of 98 per cent mustard were ob- 


Table 2. Operating data from steam distillation of 
crude Levinstein mustard. Six-inch ceramic column 
packed with 8.7 ft of f-in. Raschig rings. 


Period 

A 

B 

Number of hours 

47 

53 

Feed rate, pounds crude H per hr 

25.1 

24.7 

Steam rate, pounds per hr. 

80 

78 

Steam temperatures, F 

438 

420 

Bottom of packing, F 

287 

296 

Distillate temperature, F 

79 

84 

Distillate, per 100-lb feed 

56.8 

60.5 

Residue, per 100-lb feed 

39.3 

37.3 

Unaccounted, per 100-lb feed 

Per cent H in feed 

(3.9) 

2.2 

(by vacuum distillation analysis) 

77.5 

71.4 

Melting point of distillate, C 

13.2 

13.84 

Purity of distillate, per cent H 

Per cent recovery foV/S-chloroethyl 

96.6 

98.4 

sulfide 

70.8 

83.5 


tained per 100 pounds of crude H containing 73 
per cent mustard, which is equivalent to the 
recovery of 76 per cent of the bis-(3- chloro- 
ethyl sulfide in the crude. Table 2 summarizes 


the operating data from two periods of this 
146-hour run. 28 

Similar results were obtained by CWS 33 
with a semi-works tower of larger cross sec¬ 
tion, 13.5 by 13.5 in., which reduced heat losses 
and hence decreased steam required per unit of 
feed and product. 

Table 3 is an abstract of the data, and it is 
evident that similar results were obtained in 
the two plants: a product purity ranging from 
97 to 99 per cent mustard, containing 72 to 82 
per cent of that in the crude H. The purity of 
the product appears to depend on variations in 
the nature of the low-volatility impurities 
rather than on the per cent mustard in the 
feed. 


Table 3. Performance of steam-distillation pilot plants. 



Hours 

on 

test 

Per cent 
mustard 
in 

crude 

H 

Lb dis- Distil- 
tillate late 

per purity, 

100 lb mol 
crude H per cent 

Per cent 

re¬ 

covery 


NDRC ceramic pilot plant 


Best feed 

13.0 

70.9 

57.5 

99.0 

80.3 

Worst feed 

54.5 

77.5 

57.9 

96.6 

72.2 

Average on 






test 

146.5 

72.9 

57.2 

97.9 

76.8 

CWS development laboratory, 

brick semi-works 

Best result 

10.0 

73.3 

60.8 

98.2 

81.5 

Average 

42.5 

74.0 

53.8 

96.5 

70.2 

Average 

36.3 

74.6 

55.9 

97.8 

73.2 

Average 

34.0 

73.4 

55.5 

97.4 

73.7 

Average on 






test 

112.8 

74.0 

55.0 

97.2 

72.2 


Edgewood stability tests 43 later showed that 
the distillate described in Table 2, when stored 
in uncoated M74 bombs at 65 C, does not 
corrode the bombs excessively nor is a signifi¬ 
cant portion of the steam-distilled H decom¬ 
posed in six months’ time. 


103,5 Pentane Detarring 

In this process the crude Levinstein-H is 
contacted with liquid pentane in a counterflow 
extraction tower at ordinary temperatures; 










56 


LEVINSTEIN-H 


upon distilling off and recovering the volatile 
pentane from the purified mustard and inhibit¬ 
ing with hexamine, a stable product (see Table 
1) is obtained. 29 This process gives a higher 
per cent recovery of the pure agent from the 
crude than steam distillation (96 per cent 
versus 75 per cent), but the product has 
lower purity (89 per cent versus 98 per cent). 
Both products inhibited with hexamethylene 
tetramine are very stable, and both processes 
were carried through the pilot plant stage. 
While both steam distillation and pentane 
detarring were successful, the advantage of the 
higher purity obtained by steam distillation 
was thought to be more important than the 
higher recovery obtained in pentane detarring. 

10 3 6 Pentane Extraction 

Because of the different chemical nature of 
mustard and the impurities contained in H, it 
appeared practical to separate the two by 
solvent extraction. An extraction column was 
operated in the laboratory using pentane as 
solvent, with a contacting section consisting of 
6 ft of 14 -in. glass rings with feed near the 
middle and a “reflux” of depentanized product. 
Products containing 95 to 96 per cent mustard 
were obtained, but the calculated tower heights 
for plant-scale operation were very large. Ex¬ 
tracts obtained, even with added hexamethylene 
tetramine, were less stable and more corrosive 
to iron than the products obtained by either 
pentane detarring or steam distillation. 


10 3 7 Vacuum Distillation 

Distillation at low temperature has long 
been the classical method of obtaining pure 
bts-/?-chloroethyl sulfide in the laboratory, but 
it was not considered a practical plant process 
because of the complexity of the required vacu¬ 
um equipment in relation to the simplicity of 
the steam distillation equipment. The avail¬ 
ability of idle Lewisite plants made it possible, 
however, to proceed with large-scale purifica¬ 
tion of H by vacuum distillation of water- 
washed crude, 36 * 49 ’ 57 and a plant of this type 
was installed at Rocky Mountain Arsenal. 


10 4 THICKENING OF H 

1041 Introduction 

The technique of spraying a liquid from air¬ 
craft had been developed by the CWS in the 
years preceding World War II, and trials in 
Algiers and at Muroc Lake 1 had indicated that 
vesicant spray from high altitudes might be 
practical. Levinstein-H is relatively nonvola¬ 
tile, but only the larger drops will reach the 
ground from high altitudes without being 
largely or wholly evaporated. In 1941 it was 
learned that the British had been able to in¬ 
crease the mean drop size of the spray by 
thickening the liquid H. This was accomplished 
by the addition of 2 per cent crepe rubber, or 
8 to 10 per cent of chlorinated rubber, to H 
containing benzene, and the conclusion was 
reached that the amount of thickener should be 
such as to result in a viscosity of the thickened 
H of 6 poises at 10 C. It was urgently desired 
to develop a practical method of thickening H, 
and other vesicants, so as to obtain casualty 
producing spray from high altitudes. It was 
anticipated that such a thickened vesicant 
might also prove to be preferable for low- 
altitude spray, and that thickened agents 
might be employed in bombs and shells to in¬ 
crease the casualty producing effect of the 
dispersed liquid. Work on this problem 
proceeded with close cooperation between CWS 
and NDRC. 

10 4,2 Selection of Thickening Agent 

The use of rubber or its derivatives was 
ruled out because they were not available, and 
a large number of alternatives were studied 
by screening tests. As a group, the various 
synthetic polymers showed the most promise, 
but the majority proved to be insoluble in H. 
Others were soluble but caused little viscosity 
increased The most promising polymers ap- 

a Among the 70 or more rejected materials were: 
polyvinyl chloride, chlorovinyl chloride, Neoprene, 
Vistanex, Polybutene B-12, Alvar, Formvar, Butvar, 
butyral vinylate, copolymer of vinyl chloride and vinyl 
acetate, butyl-isobutyl methacrylate, ethyl methacry¬ 
late, propylene glycol, diglycol stearate, Glucarine, 
Napalm, lignin, polystyrene (of low molecular weight), 
Venice turpentine, glycerin, and an equimolar mixture 
of 2-isovaleryl-l,3-indanedione and n-monodecylamine. 




THICKENING OF H 


57 


peared to be methyl methacrylate and poly¬ 
styrene of proper types. 

Figure 1 shows the viscosity of H contain¬ 
ing varying percentages of several of the better 
polymers. (The unthickened material has a 
viscosity of about 0.08 stoke at 10 C.) Since 



0 /23456789 


PER CENT BT WEIGHT 

Figure 1. Viscosity of H containing several 

polymers. 

the thickened solutions show non-Newtonian 
behavior, the viscosities reported vary with the 
rate of shear obtained in the test viscometer. 
It is evident that the polymer NDR 163 is 
effective in producing a viscosity of 6 poises 
at 10 C with only 1.1 per cent concentration 
by weight in H. 

Tests with polystyrene and with methyl 
methacrylate from various sources showed 
widely varying thickening powers, and this 
was traced to variations in molecular weight. 
The polymer P-1 is a commercial methyl 
methacrylate having a molecular weight of 
about 40,000, while the sample NDR 163 is an 
experimental polymer with a molecular weight 
of over 300,000. The greater thickening power 
of NDR 163 is evident from Figure 1. The 
same effect is noted in the case of polystyrene, 
where NDR 157 has the higher molecular 
weight. 

The thickening effect as indicated by the 


viscosity was related to practical drop-size 
distribution in two ways: by a laboratory test 
mortar and by field trials with low-altitude air¬ 
craft sprays. The former 1331 consisted of a 
small cylindrical cavity from which about 2 
cu cm of sample was expelled by means of a 
piston driven forward by the explosion of a 
blank cartridge. The liquid was expelled hori¬ 
zontally and the drops formed collected on a 
test paper about 3 ft wide and 25 ft long. A 
count of the drop stain-size distribution and a 
correlation between drop and stain sizes yield¬ 
ed a drop-size distribution for the test material. 
Results with aircraft spray and with the 
mortar showed a reasonably good correlation 
between the results by the two methods, and 
the mortar was used in many screening tests 
to reduce the number of necessary field trials. 
Tests with the mortar showed that the per¬ 
centage of the charge falling in the desired 
range of 1.5- to 5.0-mm diameter passed 
through a maximum as the molecular weight 
increased. In the case of methyl methacrylate 
this maximum is in the vicinity of 200,000. 
When methyl methacrylate sheet scrap (Lucite 
and Plexiglas) became available from aircraft 
factories, it was found to have a molecular 
weight varying from 100,000 to 380,000, and 
to be entirely acceptable as a thickening mate¬ 
rial. Methacrylate sheet scrap was adopted 
and standardized as the thickening material 50 
to be used with H. 

A number of the thickening agents showing 
the greatest promise on the basis of laboratory 
mortar tests and viscosity data were tested in 
a series of field trials at Edgewood in August 
1943, using M-10 wing tanks at an altitude of 
75 to 100 ft and an airplane speed of 200 mph. 
Drop cards were used to obtain drop stains 
and drop counts, and drop-size distributions 
were reported. 26 (See Figure 2.) One of the 
most significant results of these tests was the 
demonstration that viscosity alone was of little 
value as a criterion of proper thickening. It 
seemed clear that the degree of shatter of the 
liquid leaving the tail pipe of the spray tank 13 
was dependent on the structure of the liquid 

b Shatter occurs and drop-size distribution is deter¬ 
mined at this point; subsequent breakup of drops in 
falling through the air is negligible. 




















































58 


LEVINSTEIN-H 


imparted by the polymer, and that the quality 
of structure was more important than vis¬ 
cosity. Both British and NDRC workers 618,52 
have attempted to isolate the rheological fac¬ 
tors involved, but with only partial success. 
The field tests pointed to high molecular weight 
methyl methacrylate as the most promising 
thickener, but the effective concentration was 
shown to be approximately 0.75 per cent in H 
containing 15 per cent benzene, and this solu¬ 
tion had a viscosity of only 0.5 poise—much 
less than the 6 poises originally thought nec¬ 
essary. 

In the course of the exploratory work on pos¬ 
sible thickening agents it was found that low 
concentrations of suspended fibers might be 
effective, and the mortar tests showed good 
drop-size control in the case of some samples 
of ground newspaper and asbestos fibers. After 
considerable laboratory study these were in¬ 
cluded in the 1943 field test program, but the 
results were disappointing. In the case of the 
fibers tested, the fiber concentration necessary 
to obtain good drop-size control was somewhat 
higher than the maximum for smooth dis¬ 
charge of the thickened material through the 
tail pipe of the spray tank. In view of the 
successful results with polymers, the experi¬ 
ments with suspended fibers were discontinued. 


Preparation of Thickened H 

When stored in munitions, thickened H 
[HV] is somewhat less stable than H without 
additive, and plant filling with HV seemed 
impractical where munitions might be expected 
to be stored in the tropics for a year or more. 
Accordingly, it was planned to adopt the proce¬ 
dure of “field filling ,, in which a solution of 
the polymer in benzene was added to a con¬ 
tainer of H in the field and incorporated by 
simple stirring. It was anticipated that this 
technique would be employed for filling air¬ 
craft spray tanks, and possibly M47 bombs. 
In preparing batches of HV for field trials at 
Dugway, it was found that certain plant 
batches of H were incompatible with the solu¬ 
tions of methyl methacrylate in benzene, and 
that a tarry deposit was formed. A large num¬ 


ber of samples of stored H were obtained and 
tested, showing that this behavior was rela¬ 
tively common, especially in batches of H con¬ 
taining large amounts of iron. Most of the 
stored H showed more than the maximum of 



m 





§ 





1 





i 





m 





W 

UNTHICKENED 
LEVINSTEIN H 



EH 

- 

I 

TEST NO. 36 

AT EDGE WOOD 

ARSENAL 

ON 6/16/43 







W/ 





1 

'V/V/ 



'Zul 

m. 

m 




Til III 1 1 1 



COMPARISON OF DROP SPECTRA 

OF THICKENED AND UN THICKENED 
LEVINSTEIN H 
































THICKENED 
LEVINSTEIN H 









1 1 1 









TEST NO. El 

AT EDGE WOOD 

ARSENAL 

ON 6/IE/43 




























W/. 

§ 

H 

Y//t 









W/ 


l 

w 

"" 

M. 

V7Z 






i 

I 

m. 

'////, 

rrri 

W// 

m 

W 

m 

i 





DIAMETER OF DROPS , MILLIMETERS 


Figure 2. Comparison of drop spectra of thick¬ 
ened and unthickened Levinstein-H. 


0.25 per cent iron as FeCl 2 permitted by H 
specifications. Laboratory tests showed the 
formation of an insoluble iron-polymer com¬ 
plex, and it appeared that it might be necessary 
to remove the iron from the H to be thickened 
if methyl methacrylate were to be used. This 
could be done at the plant by ammonia treat¬ 
ment and by other methods, 56 but large stores 
of H existed which could not be plant 
processed. 

Fortunately, the problem of thickening high 
iron content H was solved by the discovery 
that certain pyridine-type nitrogen bases avail¬ 
able in quantity as by-products from the 
petroleum and coal tar industries, served as 
effective iron deactivators and permitted thick¬ 
ening of the poorer grades of H with methyl 
methacrylate without deposition of a tar. 

The specifications relating to the procure¬ 
ment of the polymer 38,50 called for a methyl 
methacrylate of such a degree of polymerization 
that a 5 per cent solution in benzene would 
have a viscosity of 8 to 25 stokes at 25 C. The 
VV solution is made 42 by dissolving in benzene 
4 to 6 per cent of this polymer, ground to pass 
a 16-mesh screen, together with 11.3 per cent 
of crude nitrogen bases. The final HV is pre¬ 
pared by blending 15 parts by weight of the 





















































STABILITY OF THICKENED H 


59 


VV solution with 85 parts of H containing 1 
per cent hexamethylene tetramine (hexamine). 
Thus the final HV contains 0.6 to 0.9 per cent 
polymer, 1.7 per cent nitrogen bases, 12.7 to 
12.4 per cent benzene, and 85 per cent of H 
stabilized with 1 per cent of hexamine. It has 
a viscosity of 0.4 to 0.6 poise at 10 C. 

In order to avoid the use of a solvent such 
as benzene, it is possible to prepare a con¬ 
centrated solution of polymer in distilled H 
[HD] and to use this in place of VV. This 
procedure, developed at Edgewood Arsenal, 
involves the preparation of a thick solution 
known as HVV, containing 2 per cent polymer 
and 10.0 per cent nitrogen bases. As in the 
case of VV, 15 parts of HVV are blended with 
85 parts H, to produce an HV having a vis¬ 
cosity of about 0.5 poise at 10 C. 


105 STABILITY OF THICKENED H 54 55 

Because of the inherent instability of H, the 
problem of storage was at all times one of 
great urgency and importance. CWS discov¬ 
ered the important effect of hexamethylene 
tetramine as a stabilizer, and essentially all 
stored H was stabilized with 1 per cent added 
hexamine. This inhibitor has a marked effect 
in retarding H decomposition, and is especially 
valuable in reducing or eliminating pressure 
development. The CWS agent HN-3 was also 
found to be effective in a similar way. 

Since H is frequently acidic, and since iron 
salts accelerate H decomposition, the stability 
is much better in glass or lined containers than 
in steel. Suitable shell lining materials were 
developed under an NDRC contract (see Chap¬ 
ter 17) and specifications 24 issued. As might 
be expected, the stability of H in steel con¬ 
tainers varies widely with the container size, 
the rate of decomposition varying roughly with 
the ratio of wetted surface to liquid volume. 
Stability in unlined 1-ton containers was found 
to be quite good, whereas the storage life of H 
in an unlined 75-mm shell at 65 C is less than 
one month. For these reasons the tests in 75- 
mm shell were considered valuable as repre¬ 
senting the worst storage conditions. 

The temperature 65 C was arbitrarily chosen 


for most stability tests, and a material standing 
up well for three months in 75-mm shell at 65 
C was generally accepted as having satis¬ 
factory stability. Decomposition usually 
proceeds rapidly once it starts, so that curves 
of melting point and H content versus time 
are horizontal during an initial period and 
then dip sharply. For this reason stability re¬ 
sults for several samples should not be com¬ 
pared on the basis of per cent decomposition 
after a definite time; a more significant com¬ 
parison is that of the times to reach a specified 
per cent decomposition. 

Levinstein-H containing 1 per cent hexa¬ 
methylene tetramine is stable for four months 
at 50 C and for 6 to 8 weeks at 65 C in unlined 
75-mm shell. It is probably stable for at least 
one year in unlined 1-ton containers in the 
tropics. The stability at 65 C in unlined 75-mm 
shell is increased to four months if hexa¬ 
methylene tetramine is added directly to the 
shell. Ammonia-treated H is stable for three 
months at 65 C in unlined 75-mm shell without 
hexamethylene tetramine. The marked advan¬ 
tage of the lined shell is indicated by the fact 
that H containing 1 per cent hexamethylene 
tetramine lost less than 2 per cent in H content 
in six months at 65 C when stored in 75-mm 
shell lined with a bakelite-type lacquer. It is 
evident from these data that Levinstein-H has 
quite satisfactory stability if hexamethylene 
tetramine is used as an inhibitor and properly 
lined containers are employed. 

The stability of pure mustard obtained by 
the thiodiglycol process or by the purification 
of H is much better than that of H. Thus 
thiodiglycol mustard shows only about 3 per 
cent decomposition in unlined 75-mm shell at 
65 C in six months, but the pressures devel¬ 
oped are similar to those obtained with H (200 
to 300 psi). Hexamethylene tetramine reduces 
both decomposition rate and pressure develop¬ 
ment. The stability of steam- or vacuum-dis¬ 
tilled H [HD] is similar to that of thiodiglycol 
mustard; the rate of decomposition is some¬ 
what greater but the pressures developed are 
less. With only 0.2 per cent hexamethylene 
tetramine in steam-distilled HD, the loss in 
mustard content is but 0.4 per cent per month 
at 65 C, but the HD must be essentially water- 




60 


LEVINSTEIN-H 





Figure 3. Correlation of data on diffusion to and from spheres. 



























































































































































































TACTICAL USE OF VESICANTS 


61 


free if the hexamethylene tetramine is to be 
effective. 

The stability of thickened H in contact with 
bare steel is poor at elevated temperatures. 
Laboratory tests have shown HV containing 
hexamethylene tetramine to be stable for 20 
weeks in steel at 50 C, but in general the 
viscosity stability in contact with bare steel is 
not so good as the chemical or pressure 
stability of unthickened H. In glass, however, 
HV has shown a maximum of 33 per cent 
change in viscosity after 99 days at 65 C, and 
the stability in lined steel containers should be 
nearly as good. Thickened HD is somewhat 
better, but even this cannot be expected to 
retain its original viscosity for more than a 
few weeks in lacquered 75-mm shell at 65 C. 
Laboratory data 52 using coated steel test pieces 
providing the same ratio of metal surface to 
liquid volume showed excellent stability for 
three months at 65 C in nine out of ten samples 
of H and HD containing nitrogen bases and 
hexamethylene tetramine. 

The available data appear to be inconclusive 
as to whether thickening at the plant is prac¬ 
tical or not. The limit of stability of HV in 
lined M47 bombs is perhaps 3 to 6 months at 
65 C if hexamethylene tetramine is used; this 
may correspond to anything from six months 
to several years actual storage. Certainly more 
conclusive stability data should be obtained 
before thickening at the plant is standardized, 
and it may well develop that more stable thick¬ 
eners are required. In this situation a change 
from Levinstein-H to purified H is not the cure, 
since the storage life appears to be determined 
by the thickener and not by chemical stability 
or pressure development. The use of pure H, 
however, would simplify the search for a more 
stable thickening agent. 


io.6 TACTICAL USE OF VESICANTS 

The development of munitions and their tac¬ 
tical use has been primarily the responsibility 
of CWS, but practical problems relating to the 
use of vesicants have required laboratory in¬ 
vestigations other than those outlined above. 
In addition to the critical reports of the joint 


CWS-NDRC Committee on the “Tactical Use 
of Vesicants,” this section issued a general 
report on airplane vesicant spray. 25 

In the early stages of World War II the 
British recognized the greatly increased effec¬ 
tiveness of large drops for anti-personnel use 
of vesicants, and recommended the range of 
drop sizes from 1.5 to 5 mm. Essentially no 
drops larger than 1.0-mm diameter are pro¬ 
duced in the case of H sprayed from any alti¬ 
tude. The vapor hazard of the H hitting the 
ground is not greatly dependent on drop size, 
but evaporation is more rapid from ground 
contaminated with fine spray. A heavy spray 
(greater than 5 grams per sq m) of unthick- 
ened H will produce heavy casualties among 
lightly clothed troops in the open, but it 
seems probable that larger drops are re¬ 
quired to produce casualties among heavily 
clothed men. A number of field trials using 
spray against troops has been run both at 
Suffield and at Dugway, and a report 46 of the 
U. S. Chemical Warfare Committee concludes 
that unthickened H is satisfactory for low- 
altitude spray. However, the available field 
test data are inadequate to relate quantitatively 
the various factors such as contamination den¬ 
sity, drop size, nature of clothing and protec¬ 
tion, and probability of casualties. 

In the case of spray from altitudes above 
1,000 ft, thickening is essential to make aim¬ 
ing possible, and to reduce loss of vesicant by 
evaporation during fall. Experiments to deter¬ 
mine rates of evaporation and terminal veloci¬ 
ties were undertaken, but it was found that the 
literature was sufficiently complete so that 
relatively few new data were needed. Figure 3 
shows the results of a general correlation 2 on 
the basis of which the rate of evaporation from 
spheres may be predicted. Here the ordinate is 

• = kcP ( JL Y /3 

J ~ up B M \ pb ) 

and the abscissa is the Reynolds number Dup/p, 
for the relative motion of a sphere through air. 
The symbols are defined as: 
k c = evaporation coefficient, gram mole/sec 
(sq cm) (gram mole/cu cm). 

P = total pressure, atm. 



62 


LEVIN STEIN-H 


Pbm = mean partial pressure of air in the gas 
film surrounding the sphere, atm. 
u = velocity of sphere through air, cm/sec. 

/jl = air viscosity, poises. 

p = air density, gram/cu cm. 

b = diffusity of vapor in air, cm 2 /sec. 

D = drop diameter, cm. 

In the case of H, the group p/ P b is approxi¬ 
mately 2.5 and is independent of pressure. 
From the known vapor pressure of H (the wet 
bulb effect in cooling the drops is negligible), 
the rate of evaporation can be determined from 
this correlation for any diameter and velocity. 
Drag coefficients for spheres are well known, 2 
and the correlations in terms of Reynolds num¬ 
ber give reliable terminal velocities. Drag 
coefficients for the largest drops are larger 
than indicated by the general correlation, but 
these large drops are flattened and tend to 
break up. The largest stable drops are not 
spheres, but the correlations hold reasonably 
well. The nature of the calculated results, ob¬ 
tained by the method outlined, is indicated by 
the following values for per cent vaporization 
of pure mustard in falling from high altitudes. 

Table 4. Per cent evaporation of pure 6fs-/3-chloroethyl 

sulfide in fall from various altitudes. (20 C) 


Original drop diameter, mm 


Elevation, ft 

6.0 

2.0 

1.0 

0.5 

0.3 

1,000 

0 

1 

2 

12 

42 

5,000 

1 

4 

13 

59 

100 

10,000 

1 

8 

28 

100 

100 

20,000 

1 

16 

56 

100 

100 


Table 4 indicates the necessity of thickening 
in the case of high spray. Similar figures have 
been obtained by British workers. Vaporization 
of H is somewhat less than for pure mustard, 
since the nonvolatile impurities give a residue 
having some 70 per cent of the original drop 
diameter, and the velocity of fall is increased. 

In order to determine the possible effect of 
thickening on rate of evaporation, data were 
obtained on weight loss of single drops sus¬ 
pended from a quartz spiral spring 52 hanging 
in a stream of air. For pure mustard and H 
containing 5 per cent chlorinated rubber no 
difference in rate was noted. A mixture of 47.5 
per cent H, 47.5 per cent lewisite, and 5 per 


cent chlorobenzene likewise showed no appreci¬ 
able effect of thickening with polystyrene, 
methyl methacrylate, or isobutyl methacrylate. 

Penetration of cloth by drops of thickened 
and unthickened liquids was investigated by a 
photographic technique which gave pictures of 
the drop on impact after a free fall of 5 ft. 
With open fabrics, streamers of thickened 
liquid would protrude momentarily through the 
lower side of the cloth, only to be withdrawn 
immediately back into the fabric by surface 
tension. Closely woven fabric of either cotton 
or wool absorbs the drops completely without 
even momentary penetration. Silesia cotton 
lining, OD Pc.244, is an example of a border¬ 
line case showing slight momentary penetra¬ 
tion. Figure 4 illustrates the effects obtained. 



Figure 4. Absorption of a falling drop of liquid 
H by Silesia cotton lining, OD Pc 244. 


10 7 CHEMICAL NATURE OF 

LEVINSTEIN-H 

Research on the chemical nature of Levin- 
stein-H fell within the province of Division 9. 
It may be noted, however, that work on this 
subject was carried out in connection with the 
studies of H purification and vesicant thick¬ 
ening. 19 - 52 Residues obtained by the molecular 
distillation of Edgewood Levinstein-H were 












LESS PERSISTENT VESICANTS 


63 


shown to have chemical and physical properties 
essentially identical to those of HS 6 . 


108 LESS PERSISTENT VESICANTS 

1081 Introduction 

Although mustard gas is one of the most 
effective and practical war gases, it has very 
important limitations. Since the vapors are 
readily adsorbed by activated charcoal, troops 
wearing masks may become casualties only by 
direct contact with the liquid or by extended 
exposure to the vapor. Offensive use of the 
vapor has not been generally practical because 
munitions for vapor generation have not been 
perfected, and evaporation of H deposited on 
soil or leaves is too slow to generate toxic gas 
clouds in a short time. 

Dosage of H vapor is expressed in terms of 
the product Ct, where C is the concentration of 
H in air expressed as milligrams per cubic 
meter, and t is the exposure time in minutes. 
With masked troops at 60 F, the Ct must be 
1,000 to 2,000 to produce a high proportion of 
casualties. The corresponding range for 
masked troops at 90 to 100 F is only 300 to 500. 
If a low-flying plane flying cross-wind contami¬ 
nates a long, narrow strip of ground 50 yd 
wide to a density of 12 grams H per sq m, the 
ultimate Ct 100 yd downwind from the upwind 
edge of the strip is about 430, but a Ct of 320 
is reached only after 2 hours. These estimates 
are based on Porton Memorandum 2515, as¬ 
suming 2.0-mm drops, a wind velocity of 10.9 
mph, and a ground temperature of 90 F. It is 
evident that masked troops might spend up to 
an hour or more in the area immediately down¬ 
wind from such a spray deposit of H without 
becoming casualties. 

Levinstein-H vapor is clearly more effective 
for offensive use in tropical than in cold 
climates, but an equally good vesicant of less 
persistence would have very much greater 
value. One approach is to develop a new agent 
having a greater vapor pressure than H, and 
this has, of course, been attempted. Still an¬ 
other approach is to modify H so as to cause it 
to vaporize more rapidly. This latter led to 


the development of the mixed agent known as 
HP, which, though not perfected, has shown 
remarkable promise. 


10 8 2 Development of HP 

The research under NDRC leading to the 
HP formulation was based on the idea that an 
additive might be incorporated into H, which, 
on exposure to the atmosphere, would react 
with the moisture or oxygen of the air to 
produce heat, thus raising the temperature and 
causing an increase in the rate of vaporization. 
In practically all the work the additive was 
white phosphorus [WP], which was employed 
in small amounts in H, and which was found 
to result in liquid temperatures as high as 190 
C. The effect on the rate of vaporization of the 
active agent was, of course, enormous. Al¬ 
though the HP formulation was not developed 
to the point of adoption, the results obtained 
were quite promising. The basic idea seems 
applicable to other chemical warfare agents, 
and possibly for other purposes. 

White phosphorus is soluble to the extent of 
2 per cent at 20 C in either distilled or Levin¬ 
stein-H. The amount of WP can be increased 
by the use of a cosolvent, but attempts to 
produce stable emulsions were not successful. 
The early compositions showing promise were 
(1) a straight 2 per cent solution, and (2) a 
solution of 4.0 per cent WP, 15 per cent carbon 
disulfide, and 81 per cent H. In laboratory tests 
the liquid surface was exposed to air at a 
measured velocity, and the rate of vaporization 
obtained by absorbing the H carried away by 
the air stream. It was found that composition 
(1) evaporated three to five times as fast as 
the H control, and the enhanced rate of evapo¬ 
ration of (2) was twenty to thirty times that 
of the control. The marked effect of the WP 
was largely confined to the first few minutes of 
exposure, however, and did not hold for the 
vaporization of more than a few per cent of 
the sample. 

Various laboratory tests were designed to 
measure the effect of WP addition to H, but 
it became evident that the results could not 
be extrapolated to field conditions, since air 



64 


LEVINSTEIN-H 


velocity, nature of support for the liquid, and 
other variables, had important effects on the 
results. Accordingly, tests were run at Suffield 
in the fall of 1944, 44 - 45 using both the annulus 
technique and static bomb bursts with H and 
with the two compositions noted above as (1) 
and (2). Vapor samples downwind showed 
the average vapor concentrations to be about 
30 per cent greater in the case of the HP 
compositions than for straight H. This was 
true for the first hour; the effect of the WP 
tended to disappear with time. The bomb with 
the HP composition containing carbon disulfide 
inflamed. 

Since the nature of the support for the liquid 
seemed so important, experiments with various 
supports were undertaken. Materials were 
chosen having thermal insulating value and 
large capacity to absorb liquid H. The re¬ 
sults obtained were very remarkable. Using 
a Y 2 -in. cube of regenerated cellulose sponge 
soaked in composition (2), it was found that 
the vaporization was very rapid, and that the 
center of the sponge reached temperatures as 
high as 190 C. The H evaporated amounted 
to 30 to 40 per cent in 300 sec, and careful 
chemical analyses proved that the H vaporized 
had not been decomposed. The H was gener¬ 
ated as a dense smoke cloud, with a slight 
phosphorescent glow but no flame on the cellu¬ 
lose sponge. Similar results were obtained 
without cosolvent by dissolving 4 per cent WP 
in H at 50 C before saturating the sponge. 
Other materials were tested as supporting 
media, including glass fiber, Neoprene sponge, 
wood shavings, blotting paper, puffed rice, ver- 
miculite, Santocel, cotton, and wool. The cellu¬ 
lose sponge with pores about 1-mm diameter 
seemed best, but was not chemically stable on 
storage in contact with H. The most promis¬ 
ing support which was both effective and 
stable was wool in the form of fabrics or bats. 

The use of carbon disulfide makes the wet 
sponges have a tendency to inflame, so a 
search was made for a nonvolatile cosolvent. 
Cyclic ethylene trithiocarbonate was found to 
be excellent, and was used in the composition 


(3) : 81.5 per cent H, 3.5 per cent WP, and 
15 per cent cyclic ethylene trithiocarbonate. 
This composition on i/^-in. cellulose sponges 
vaporizes to the extent of about 50 per cent 
in 5 minutes, with copious clouds of H smoke, 
and the reaction starts immediately on ex¬ 
posure to air, with no induction period. Labo¬ 
ratory tests show the rates of vaporization in 
the early stages to be 3.5 to 10 times that of 

H, when the liquid is supported on soil or leaves 
instead of on sponges. Toy mortar shots 
showed no tendency of the atomized liquid to 
inflame. The vaporization of the liquid from 
soil or leaves in air at 20 C amounts to 1 to 3 
per cent in 20 minutes, as compared to 0.3 per 
cent for H. 

The problem of locating a suitable absorbent 
support in order to obtain the greatly increased 
vaporization rates has not been solved. Cellu¬ 
lose sponge is effective, but is not stable on 
storage with HP. The amount of the agent 
expelled as a liquid when a bomb explodes is 
probably excessive with materials such as cel¬ 
lulose sponge. Preliminary bursting tests have 
indicated that 18 to 37 per cent of the liquid 
is retained by Neoprene sponges. Combining 
the laboratory data on rates of vaporization 
of HP from sponges and from the liquid dis¬ 
tributed on soil and leaves with this figure 
for liquid retention on explosion, it is esti¬ 
mated that the total H vaporization in 400 sec 
should be 3 to 5 per cent, as compared with 
0.07 per cent in the same time period for H. 
Under conditions where a lethal Ct of 1,000 to 

I, 500 is obtained in 2 to 3 hours with H, the 
same Ct should be obtained in a very few min¬ 
utes, using bombs charged HP on porous sup¬ 
ports. 

The basic idea of HP should be applicable 
to other agents. WP is soluble to the extent 
of 1.2 per cent in HN-3, and the use of co¬ 
solvents should make it possible to increase 
this concentration. WP appears to be the best 
additive, but others are possible. Trialkyl 
borines, stibines, and arsines provided by Divi¬ 
sion 9 were tested with H, but showed little 
promise. 



Chapter 11 

EXTERIOR BALLISTICS OF LIQUID-FILLED SHELLS 


111 SUMMARY 

T he complicated problems of the exterior 
ballistics of liquid-filled shells have been 
attacked, with special reference to the 4.2-in. 
chemical mortar shell, by (1) a study of the 
existing theory and data on liquid-filled shells, 
(2) experiments with a liquid-filled spinning 
top, using cavities of three shapes, liquids of 
various densities and viscosities, and internal 
vanes of several types, (3) field trials with 
1-in. models of the 4.2-in. mortar shell, and (4) 
the design and construction of a laboratory 
ballistics testing machine in which full-sized 
shells supported on gimbals may be subjected 
to the various forces simulating flight along a 
curved trajectory. The testing machine has 
been completed and experiments with it will be 
made under a continuation of the contract by 
CWS. 

The proof-firing data and the results of the 
tests with the 1-in. models indicate that the 
4.2-in. shell may be stable near the gun, but de¬ 
velop instability at or beyond the vertex caused 
either by excessive spin (excessive stability) 
making the shell fail to follow the curved tra¬ 
jectory, or by excessive yaw developing near 
the vertex, which causes the shell to tumble. 
The experiments with the top indicated the 
effect of internal vane design in causing erratic 
nutational motion in a shell which was stable 
in the ordinary sense. Large momentary yaws 
developed at speeds well above the critical with 
certain vane designs, and this effect may well 
explain tumbling of shells with high stability 
factors. 

112 INTRODUCTION 

There exists a very considerable background 
of theory and experience relating to the flight 
characteristics of solid shells, and their tra¬ 
jectories may be predicted with a fair degree 
of certainty. Motion along flat or curved tra¬ 
jectories may be calculated, provided the angle 
of yaw does not become greater than about 15 


or 20 degrees. Conditions for stable flight of 
liquid-filled shells are but partially understood, 
and the problem has become urgent because of 
the erratic behavior of some of the important 
chemical munitions. Liquid filling complicates 
the theory of solid shells by introducing such 
factors as liquid viscosity, liquid density, and 
internal baffle vane design. 

The motion of a solid spinning projectile is 
similar to that of a top spinning on a fixed 
pivot. 11 - 12 The spin causes the shell to retain 
its general orientation with respect to the 
earth, but a precessional motion develops which 
causes the angle of yaw to increase and de¬ 
crease. As yaw develops, the air pressure 
causes a force to be applied to a center of pres¬ 
sure ahead of the center of gravity, and an 
overturning moment develops which may in¬ 
crease the yaw and cause the shell to tumble. 
The condition for stability at small angles of 
yaw is 

A 2 N 2 

— = Stability factor >1.0 
4 B^g c 

where A = moment of inertia about the spin 
axis. 

B = moment of inertia about the trans¬ 
verse axis through the center of 
motion. 

N = spin velocity. 

fx = overturning moment coefficient 
(overturning moment =/x times sine 
of angle of yaw). 

g c = gravitational conversion factor. 

Shells are usually designed so that the sta¬ 
bility factor will be greater than 1.4. If it is 
much above 2.0, the stability may be excessive, 
causing failure of the shell axis to follow the 
curved trajectory. This is especially noticeable 
at high angles of fire, at which shells with high 
spin “sit down” on their bases, because they 
maintain too closely their original orientation 
with respect to the earth. 

Data on firing trials with liquid-filled 75-, 
105-, and 155-mm shells, made available by the 
Ballistics Research Laboratory at Aberdeen, 


65 



66 


EXTERIOR BALLISTICS OF LIQUID-FILLED SHELLS 


show no important differences between the re¬ 
sults with HE and liquid fillings. The stability 
problem in the case of the 4.2-in. mortar shell 
is quite different, however, since the ratio of 
liquid weight (H-filled) to total filled weight is 
0.26, as compared to ratios of 0.075, 0.097, and 
0.124 for the 75-, 105-, and 155-mm shells, re¬ 
spectively. Certain types of the 4.2-in. shell 
have been found to be stable 4 when employed 
with solid filling, but unstable with liquid fill¬ 
ing. Such shells (E49R1) without internal 
vanes have been found stable when filled with 
7.0 lb solid WP, but unstable when filled with 
7.0 to 7.1 lb liquid chlorosulfonic acid. When 
the liquid content was reduced to 5.8 to 6.0 lb, 
the shell became stable. That the internal vane 
has a stabilizing influence is indicated by the 
fact that a vaned shell (E38R2) containing 
7.8 lb chlorosulfonic acid was stable. Almost 
no proof-firing data exist as a basis for demon¬ 
strating the effect of the viscosity of the liquid 
filling. The effect of void space is apparently 
complicated, as the proof-firing data relating 
to this variable are quite contradictory. 5 ’ 6 ’ 13 * 14 ' 15 
The most advanced analytical treatment of 
the exterior ballistics of liquid-filled shells is 
that of E. A. Milne. 5 Milne’s theory is de¬ 
veloped on the basis of a projectile with an 
ellipsoidal cavity having its center coincident 
with the center of gravity of the shell, filled 
with an ideal liquid of zero viscosity. Two di¬ 
mensionless parameters are developed which 
divide stable and unstable shells, assumed to 
be following a flat trajectory with negligible 
overturning moment. In spite of the simplify¬ 
ing assumptions introduced, the two parame¬ 
ters were found to serve as an empirical 
basis of distinguishing stable and unstable de¬ 
signs of actual shells. As applied to United 
States shells, the method indicates that the 
105- and 155-mm shells should be unstable 
without burster wells. The Milne criterion of 
stability apparently does not apply in the case 
of shells such as the 4.2-in., which has a high 
ratio of weight of filling to total filled weight, 
and which has a burster well and internal 
vanes. The Milne theory, however, is being 
extended by the staff of the Ballistics Research 
Laboratory to allow for flight along a curved 
trajectory, and for cases where the centers of 
gravity of shell and filling do not coincide. 


It has been pointed out a that the observed 
instability of the 4.2-in. shell may develop at 
the vertex of the trajectory, beyond the region 
in which the Milne theory applies. As the cur¬ 
vature of the trajectory increases rapidly, there 
develops a steady yaw away from the plane of 
the trajectory, and calculations indicate that 
the yaw of the 4.2-in. shell near the vertex may 
become quite large. It is suggested that erratic 
internal liquid motion or negative aerodynamic 
damping may cause instability to develop at 
or beyond the vertex, even though motion 
along a straight trajectory is stable. 

113 EXPERIMENTS WITH A LIQUID- 
FILLED TOP 

Because of the similarity of the gyratory 
motions of a spinning shell in flight and a top 
spinning on a fixed pivot, laboratory experi¬ 
ments with a liquid-filled top were undertaken. 
The top consisted of a cylindrical steel case 
5% 2 in. long by 43i£ 2 -in. OD having a re¬ 
movable cover and pivot points on both ends. 
Three removable inserts were provided with 
cavities of three types. One was a 4Y2-in. 
spherical cavity, one was an ellipsoid with a 
ratio of major (axis of revolution) to minor 
axis of 2, and the third was a cylinder with in¬ 
ternal length and diameter both 4% in. Liquids 
of various types and in varying amounts were 
employed in the three cavities. 

The experimental top was started spinning 
on fixed top and bottom bearings. The upper 
bearing was then removed and the motion ob¬ 
served as the speed of revolution slowly de¬ 
creased due to air and bottom bearing friction. 
The speed was observed at intervals by means 
of a Strobotac until the critical speed was 
reached, when the top became unstable and fell 
over. Internal vanes of various designs were 
tested using the spherical and the cylindrical 
cavities. A short length of %-in. OD copper 
tubing on the vertical axis was introduced to 
simulate a burster well. 

The critical speed of a solid or empty top is 
readily calculated from its dynamical con¬ 
stants. The expression for the critical speed 
of a liquid-filled top is likewise easily obtain¬ 
able if the liquid is assumed to slip freely at 

a J. J. Stoker of the Applied Mathematics Panel. 




EXPERIMENTS WITH A LIQUID-FILLED TOP 


67 


the solid-liquid boundary. Figure 1 illustrates 
the two theoretical relations for the top having 
a spherical cavity filled with varying weights 
of liquids. The experimental points for several 



Figure 1. Critical speeds of spinning top con¬ 
taining liquid inside a spherical cavity. 


liquids are seen to fit the upper theoretical 
curve based on the assumption that viscosity is 
not important. The critical speed with the most 
viscous fluid (37 centipoises) is slightly less 
than the theoretical value, indicating a slight 
effect of viscosity in increasing stability. 

The tests with glycerol in the spherical 
cavity gave peculiar results. Not only was the 
critical speed less reproducible, but also the 
normal smooth precessional motion at speeds 
above the critical was interrupted by short 
periods during which the amplitude increased 
suddenly, giving violent reactions at the lower 
bearing. When the cavity was %-full of 
mercury, it could not be brought to full speed 
because of excessive vibrations, suggesting 
that the mercury might be concentrated on 
one side of the cavity. 

Similar tests with the ellipsoidal cavity gave 
results which checked the theory for rigid ro¬ 
tation, indicating that the elongated ends of 
the cavity tend to force the axis of the spin¬ 


ning fluid mass to tilt with the axis of the top. 
Erratic results were obtained with mercury, 
the motion consisting of alternate quiet periods 
of about 10 sec duration and brief periods of 
violent vibration. In the latter, intense lateral 
reactions developed at the bearings, and the 
top tended to jump out of the lower bearing. 

Using the spherical cavity and vertical single 
or double (cross) vanes, the critical speeds 
checked the theory for rigid rotation of the 
liquid. Similar results were obtained with and 
without holes in the vanes, but the precessional 
motion was smoother without the holes, and 
the spin velocity decreased more rapidly when 
the vanes with holes were used. 

Tests with the cylindrical cavity and vanes 
located parallel to the spin axis were run with 
varying fractions void. The effect of void 
fraction was found to be quite complicated and 
to vary markedly with the vane design. In the 
vicinity of 10 per cent void the critical speed 
was 2,000 rpm, yet with the central tube only 
and no vanes the critical speed was 800 rpm. 

The first conclusion from the experiments 
with the top is that the liquid does not follow 
the motion of the cavity and that it is safe to 
draw a similar conclusion for the flight of an 
actual shell. Perhaps the most important re¬ 
sult of the top experiments, however, was to 
demonstrate the erratic nutational motion fre¬ 
quently obtained at speeds well above the criti¬ 
cal, when the motion is stable in the ordinary 
sense. In the case of artillery shells, the sim¬ 
plified theory of stability—the analog of the 
exact theory for the top—fails when the yaw 
becomes large, and experiment indicates that 
a shell becomes unstable whenever the yaw 
becomes large. Erratic behavior of a liquid- 
filled shell, similar to the violent behavior of 
the liquid-filled top, may cause the shell to be¬ 
come unstable even though the analogous mo¬ 
tion of the top is still stable in the sense of 
continuing to spin at velocities well above the 
critical. 

The erratic behavior at speeds above the 
critical was common in the case of vanes set 
parallel to the spin axis, and there was a wide 
variation of critical speed with void fraction. 
In the case of single vanes, the vane is pre¬ 
sented alternately broadside and edgewise to 
the fluid when the top yaws, and the top be- 























































































68 


EXTERIOR BALLISTICS OF LIQUID-FILLED SHELLS 


haves as though its moment of inertia depended 
on its orientation with respect to the spin axis. 
The tests with varying void spaces indicated 
that best results would be obtained without 
vanes. This conclusion is not applicable to a 
shell, however, as the analogy is incomplete, 
especially for high-angle fire, since it is desir¬ 
able that the liquid’s spin axis as well as the 
shell’s axis turn at the same rate as the tan¬ 
gent to the trajectory. 

As a result of an analysis of the problem 
based on these tests, the recommendation was 
made that the 4.2-in. shell be fitted with a num¬ 
ber of perforated circular disks within the 
liquid cavity, spaced at intervals and perpen¬ 
dicular to the axis. The purpose would be to 
divide the liquid into small masses, each cap¬ 
able of turning independently of the others. A 
schedule of field trials of 4.2-in. shells with 
vanes of this type was set up, but the results 
are not yet available. Top experiments with 
vanes of this type gave the most stable motion 
of any arrangement tried, and greatly reduced 
the critical speeds for intermediate void frac¬ 
tions. 


114 EXPERIMENTS WITH 1-IN. MODELS 
OF THE 4.2-IN. CHEMICAL 
MORTAR SHELL 

In connection with the study of vane design 
in the 4.2-in. mortar shell a series of tests was 
carried out using a small model mortar at 
Aberdeen Proving Ground. This experimental 
mortar was designed to shoot 1-in. projectiles 
at high angles with a charge consisting of a few 
grains of black powder. Twelve scale models 
of the 4.2-in. shell were constructed with vari¬ 
ous types of internal vane construction. The 
empty shells weighed 146.1 to 167.0 grams and 
the volume of the cavities varied from 29.6 to 
32.4 cu cm. Four mortar barrels were used, 
having one rifling twist in 15, 20, 25, and 30 
calibers, respectively. The charge of 5 grains 
employed was sufficient to give a range of 241 ft 
with a 190-gram projectile fired at an angle of 
40 degrees. The calculated muzzle velocities 
varied from 118 to 156 fps. Several liquid 
charges were used, with various void fractions. 


A motion picture camera was employed to fol¬ 
low the shells in flight. 

With a shell 88 per cent full of ethylene di¬ 
bromide and fitted with a vane of standard de¬ 
sign and a barrel having a rifling pitch of one 
in twenty, large yaws were obtained on the far 
end of the trajectory beyond the vertex at all 
elevations above 32 degrees. True flight was 
obtained with the same shell up to angles of 
45 to 50 degrees when the rifling twist of one 
in twenty-five was used. The same shell filled 
with tetrabromethane (specific gravity 2.96) 
showed completely unstable behavior with void 
spaces of zero and 17 per cent, but the in¬ 
stability disappeared when water was used in¬ 
stead of the heavy liquid. A large increase in 
the viscosity of the charge (to 20 poises) 
showed some indication of giving better sta¬ 
bility with the standard 4.2-in. vane design. 
The effect of rifling twist was clear: at pitches 
of 1:15 and 1:20 instability developed beyond 
the apex; best results were obtained with a 
pitch of 1:25; with a pitch of 1:30 excessive 
yaw developed near the gun. 

The variables having the most pronounced 
effect on stability were the rifling pitch, the 
angle of elevation, and the muzzle velocity. The 
use of vanes of various designs changed the 
results very little. Decrease in liquid density 
or large increase in viscosity improved stabil¬ 
ity. In most of the experiments the observed 
instability was actually overstability, since the 
yaws were steady and to the right of the tra¬ 
jectory. Departure from true flight occurred 
when this steady yaw failed to disappear after 
the shell had passed the top of the trajectory. 
Instability of this type could be corrected by 
changing the rifling of the barrel to reduce 
spin, or by increasing the muzzle velocity. 
Neither of these solutions to the problem of the 
4.2-in. mortar shell were acceptable in time of 
war. 

11 5 LABORATORY BALLISTICS 
TESTING MACHINE 

Experimental ballistics studies in the field 
have proved extremely helpful in connection 
with many important problems, and the tech¬ 
nique has been developed to an advanced stage. 



LABORATORY BALLISTICS TESTING MACHINE 


69 



Figure 2. Laboratory ballistics testing machine. 







































70 


EXTERIOR BALLISTICS OF LIQUID-FILLED SHELLS 


Such tests are time-consuming and expensive, 
and require statistical analyses of large num¬ 
bers of observations. For these reasons, it is 
exceedingly difficult to study the separate ef¬ 
fects of the many variables affecting the sta¬ 
bility of liquid-filled shell, and a practical labo¬ 
ratory test technique would prove extremely 
useful. 

There appear to have been three 5,1213 previ¬ 
ous attempts to simulate the motion of a shell 
in flight by spinning a shell or shell model 
supported in gimbals so as to be free to turn 
in any direction about its center of gravity. 
These were not carried to the point of making 
careful measurements, and it appears that in 
none of the three cases were external forces 
applied simulating the forces acting on the 
shell in flight. 

With the encouragement of CWS and of the 
Ballistics Research Laboratory at Aberdeen, a 
laboratory testing machine was designed and 
constructed with the object of observing and 
measuring the nature of motion of full-sized 
shells, such as the 4.2-in. mortar shell, when 
rotated at high speeds and subjected to speci¬ 
fied forces simulating the varying overturning 
moment along a curved trajectory. A total of 
fourteen preliminary designs were prepared 
before the final design was agreed upon. Fig¬ 
ure 2 illustrates the test machine as finally con¬ 
structed. 

The 4.2-in. chemical mortar shell which 
forms the rotor is fitted with a special base and 
nosepiece which allow it to turn in ball bear¬ 
ings. The internal design is not altered, and the 
burster well is in place. The tube which en¬ 
closes the shell, the gimbal ring, and other 
moving parts are made of aluminum. The total 
transverse amount of inertia of the entire as¬ 
sembly is 745 (lb mass) (in. 2 ), as compared 
with 546 for the original shell. The moment 
about the spin axis is 40.7 (lb mass) (in. 2 ), as 
compared with 47.0 for the 4.2-in. shell. Air 
jets and small nozzles in the aluminum cage 
are used to spin the shell, and a second mani¬ 
fold and set of nozzles is used to stop the spin¬ 
ning shell after a test. At the top is an air 
piston designed to apply a thrust to a push rod 
attached to ball-and-socket joint on the nose of 
the shell, simulating an overturning moment 


approximately proportional to the sine of the 
angle of yaw. This air piston is moved slowly 
in an arc from front to rear of the figure, this 
motion approximating the varying direction of 
the overturning force as the shell follows a 
parabolic trajectory. The lead screw which 
operates the traversing drive rotates at a con¬ 
stant speed during an experiment. The crank 
and sliding nut arrangement is designed to ob¬ 
tain an angular velocity of the frame which is 
proportional to the square of the cosine of the 
angle which the frame makes with a vertical 
plane. This variation of angular velocity is 
that of a tangent to a parabolic trajectory. The 
time of movement from an initial position 45 
degrees to the vertical on one side to the final 
position 45 degrees on the other side corre¬ 
sponds to the time of flight of the shell and can 
be varied. 

A record of the shell’s motion is made by 
means of an optical system carried by the over¬ 
turning moment applicator. An interrupted 
light source produces a record on a sheet of 
photographic paper laid across the arch above 
the machine. This gives a record of the pre- 
cessional motion of the nose of the shell. The 
rotational speed of the shell is measured by 
means of a specially constructed stroboscopic 
device. 

The principle of operation is to operate a 
spinning shell under conditions simulating 
flight along a curved trajectory, with the aero¬ 
dynamic forces acting on the shell in flight 
simulated by a single overturning moment por- 
portional to the sine of the angle of yaw. The 
curved trajectory is reproduced by having the 
point at which the overturning moment appli¬ 
cator is pivoted move about the shell’s center 
of gravity at a rate equal to the angular veloc¬ 
ity of a tangent to the actual trajectory. Fig¬ 
ure 3 illustrates the nature of the data obtain¬ 
able with the test device described. Owing to 
the method of starting, this first test result is 
not typical of a shell in flight, since the nuta- 
tional motion shown is increasing. 

At the termination of the contract in the 
fall of 1945, the machine had been constructed 
but no experiments had been made with it. The 
investigation is being continued under a con¬ 
tract with CWS. 



LABORATORY BALLISTICS TESTING MACHINE 


71 





TIME OF " FLIGHT " FR0M”45° TO t45°= 8.50 SEC 
SPEED OF ROTATION = 4 200 RPM 
OVERTURNING MOMENT = 9.50 (FT)(LB)/(RADIAN) 


Figure 3. Motion of empty shell observed experimentally. (Curved locus of points represents motion 
of nose of shell as viewed end-on.) 

































Chapter 12 


HYDROGEN GENERATOR FOR PRESSURIZING PORTABLE 
FLAME THROWERS 


121 SUMMARY 

T he use of compressed nitrogen for pres¬ 
surizing portable flame throwers has the 
great disadvantage of requiring a battery of 
four nitrogen cylinders weighing 600 lb. The 
small air compressor for the purpose weighs 
820 lb, and neither the cylinders nor the com¬ 
pressor are readily transported to the front 
lines where the flame throwers are used. 

As an alternative to these methods, a high- 
pressure hydrogen generator weighing 49 lb 
was developed and procurement started in the 
spring of 1945. Hydrogen was generated by 
the chemical reaction of water and lithium 
hydride. For pressurizing one M2-2 flame 
thrower, the chemical charge consisted of 0.5 
lb granular lithium hydride in a container 
weighing 1.2 lb filled, and the salt or fresh 
water required for reaction and cooling 
weighed 2.2 lb. 


i2.2 INTRODUCTION 

Fuel is ejected from the fuel tanks of port¬ 
able flame throwers by compressed air or nitro¬ 
gen from the pressure tank of the flame 
thrower. These pressure tanks are filled to a 
pressure of from 1,700 to 2,000 psi from a bat¬ 
tery of large commercial nitrogen cylinders, 
or by the use of truck-mounted air compressors 
weighing 820 lb. This servicing must of neces¬ 
sity be done at a considerable distance behind 
the front lines, seriously limiting the number 
of missions per day of a given flame thrower. 
The desirability of a lightweight generator, 
capable of refilling the pressure tanks of port¬ 
able flame throwers near the point of discharge, 
is obvious. In addition to the time saved, the 
need for the transportation of a large amount 
of heavy equipment, per pound of available 
gas, is eliminated. 

Consideration of various methods of genera¬ 


ting gas under pressure led to selection of two 
alternatives: the reaction of a metal hydride 
with water, and the controlled burning of 
double base powders. Development of the sec¬ 
ond alternative was undertaken by the Alle¬ 
gany Ballistics Laboratory of NDRC Division 
3, and is reported elsewhere. 7 Good results 
were obtained by the first method using lithium 
hydride, calcium hydride, sodium hydride, and 
a mixture of sodium hydride and aluminum 
(see Chapter 7) ; but the first was selected be¬ 
cause of its availability and light weight, and 
because it showed no tendency to catch fire on 
exposure to the atmosphere. 

Several experimental hydride generators 
were constructed and tested at Edgewood Ar¬ 
senal in October 1944. The most promising was 
developed further and became the E5, of which 
twenty-five were procured and delivered for 
test by the Infantry Board, 2 the Marine Equip¬ 
ment Board, r ' the Airborne Board, 3 and the 
Chemical Warfare Board. 14 Adoption was rec¬ 
ommended in each case, and final drawings of 
the E5R1 were prepared by the CWS Develop¬ 
ment Laboratory. These generators were in 
large-scale production at the end of World 
War II. 


12 3 OPERATION OF THE GENERATOR 

The E5R1 generator is illustrated in Figure 
1.® In operation of the generator, a cartridge 
containing lithium hydride is loaded into the 
breech of the reaction chamber, and a sepa¬ 
rate bottle is filled with water. The water used 
to react with one cartridge is approximately 
1.2 lb. The water flows by gravity into the 
reaction chamber where it reacts with the cart¬ 
ridge. The generated hydrogen flows through 
cooling coils which lower the temperature of 
the gas to within 10 or 20 F of ambient tem¬ 
perature. The entrained water is removed from 
the gas stream by a cyclone separator at the 


72 


OPERATION OF THE GENERATOR 


73 



CHARGING LINE 
ELBOW 


NIPPLE- 


WATER JACKEL 
CAP 


AIR-COOLED 

COIL 


WATER-COOLED 
COIL 


LEG BRACKET 


REACTOR 

CHAMBER 


WATER JACKET- 


E7 

HYDRIDE 
CARTRIDGE 


TOP GUARD 


BLOW-DOWN 
VALVE 


BREECH PLUG 
HANDLE 


WATER 

-BOTTLE 

PLUG 

WATER 

BOTTLE 

ELBOW 


SAFETY 

HEAD 


PRESSURE 
GAGE 


WATER 

FEED 

VALVE 


WATER 

FEED 

LINE 


TRAP 


BREECH PLUG 
CUP / 


BREECH 

PLUG 


CHARGING LINE_ 
ASSEMBLY 


WATER 

JACKET 

DRAIN 

COCK 


LEG 


Figure 1. E5R1 hydrogen generator assembly for pressurizing flame throwers. 



















































74 


HYDROGEN GENERATOR 


top of the water bottle, and the cool dry gas 
then flows through a charging hose to the pres¬ 
sure tank of the portable flame thrower. When 
the desired pressure is reached, the excess 
water and hydrogen are released from the 
generator. The breech is opened, and the spent 
cartridge is removed and discarded. The bulk 
of the hot hydroxide residue stays in the cart¬ 
ridge so that disposal is safe and convenient. 
According to the Marine Board, 5 an average 
Marine requires 25 minutes to learn how to 
run the E5 generator. By following the direc¬ 
tions on the instruction plate attached to the 
generator, 4 to 6 cycles can be made per hour. 
With repeated runs, a maximum of 1 pound 
of water is evaporated from the jacket in each 
run; with infrequent runs little or no make-up 
cooling water is required. In emergencies, sea 
water may be used both for reaction and cool¬ 
ing. 

The final cartridge (E7 hydride cartridge) 
contains 0.5 pound of 14- to 18-mesh (U. S. 
standard screens) lithium hydride in a per¬ 
forated steel basket surrounded by a tinned 
steel sleeve open at both ends, the whole shipped 
in a key-opening, airtight can. 

The E5 generator was subjected successfully 
to various rough handling tests, including para¬ 
chute drops from an elevation of 800 ft. The 
Boards reported that the E5 generator was 
easily carried on packboard by one man over 
any terrain accessible to a man carrying a 
portable flame thrower. A second man carried 
the necessary supply of cartridges and extra 
water. 

The dimensions and weights of the E5 gen¬ 
erator are summarized in the following table. 


Weight generator, empty 49 lb 

Loaded, water in jacket, ready to run 59 lb 

Empty, in packing chest 

(16£ x 15 x 27f in.) with tools, spare parts, and 
accessories, packed for overseas shipment 100 lb 

Wooden box containing 36 lithium hydride cartridges 

(net weight 43 lb) ready for overseas shipment 78 lb 

Maximum height generator, legs retracted 24 % in. 

Maximum width generator, legs retracted 10 in. 

Maximum diameter, legs retracted 12 in. 

Maximum height, legs extended (operating position) 32 in. 


In connection with the tests by the four 
Boards, and in auxiliary tests at MIT, nearly 
1,000 chemical charges were fired in E5 gen¬ 
erators. In subsequent tests, hundreds of E7 


cartridges were fired in a single E5 generator, 
all without difficulty. Portable flame throwers, 
both M1A1 and M2-2, were successfully oper¬ 
ated with hydrogen produced in E5 hydrogen 
generators, using both thickened and unthick¬ 
ened fuel. The results equal those obtained 
with nitrogen or compressed air, and hydrogen 
has the advantage over compressed air because 
it does not form an explosive mixture in the 
fuel tanks of flame throwers. 

Table 1 summarizes the requirements for 
repressurizing M2-2 portable flame throwers. 
A comparison is made of the E5 generator and 
the conventional system that uses either cas¬ 
cade filling from large commercial nitrogen 
cylinders or repressurizing using a motor drive 
air compressor. 

Table 1 . Requirements for repressurizing M2-2 

portable flame thrower. 

Basis: 20 M2-2 flame thrower pressure cylinders 
repressurized per hr to 2,000 psi. 



Using 

nitrogen 

cyl¬ 

inders 

Using E5 
portable 
hydrogen 
generator 

Using 

portable 

com¬ 

pressor* 

Weight of unit pressur¬ 
izing device,! lb 

610t 

49 

820 

Number required 

1 

4 

1 

Total weight of pressur¬ 
izing equipment, lb 

610 

196 f 

820 

Weight of chemicals and 
containers shipped 
overseas, lb 

400J 

24 

5 

Weight of water for re¬ 
action, lb 

0 

24 

0 

Weight of water for cool¬ 
ing, lb 

0 

20 

0 

Total weight of supplies 
expended, lb 

400 

68 

5 

Total weight of gas in 
repressurized cylin¬ 
ders, lb 

22 

2 

23 

Distance flame thrower 
pressure tank must be 

Substan¬ 

Small 

Substan¬ 

carried to be filled 

tial 


tial 

Pilot hydrogen supply 
for M1A1 flame throw¬ 
er 

Note 1 

Note 2 

Note 1 


* Compressor, air, gasoline engine driven, 7 CFM, Ml. 

t If weights of crates, or volumes of shipments were included, the 
comparison would be even more favorable to the portable hydrogen 
generator. 

t This figure assumes that four 150-lb nitrogen cylinders in a 
cascade filling system are used as per the “M2-2 Flame Thrower 
Manual” (TM 3-376A). 

Note 1. Requires large commercial hydrogen cylinders, an addi¬ 
tional item of supply, or else spare small hydrogen tanks. 

Note 2. Small hydrogen igniter bottle is filled simultaneously 
with main pressure cylinder. 












DESIGN FEATURES 


75 


124 DESIGN FEATURES 

12-41 Particle Size of Lithium Hydride 

If the grains of LiH are too small, the rate 
of reaction is too rapid, seriously complicating 
the problems of heat dissipation and removal of 
mechanically entrained liquid and alkaline resi¬ 
dues from the gas produced. With excessive 
fines, the resulting rapid hot reaction leaves 
molten residues which may plug valves or cool¬ 
ing coils while the surplus gas is being blown 
off at the end of a cycle. If the grains are too 
coarse, chemical reaction is incomplete, leav¬ 
ing a core of unreacted LiH at the center of 
the oversize grain. It was established that the 
optimum grain size is 14 to 18 mesh on U. S. 
standard screens. Cartridges containing the 
recommended range of grain sizes were sub¬ 
jected to standard rough handling tests and 
found to function properly in the generator. 

Ratio of Water to Hydride 

With the standard charge of 0.5 lb of lithium 
hydride, the stoichiometric quantity of water 
for complete reaction is 1.14 lb (based on re¬ 
action to LiOH). Best results were obtained 
with 107 to 112 per cent of the theoretical, 
namely 1.21 to 1.27 lb. 

12-4-3 Cartridge 

Two types of cartridges were developed. In 
the first, large area for water access was ob¬ 
tained by charging the hydride granules in a 
cylindrical basket made from 20-mesh copper 
screen with soldered seams at top, side, and 
bottom. This basket was surrounded with a 
tinned steel sleeve closed at both ends by taped- 
on paper covers, and this cartridge (sleeve, 
basket, and hydride) was packed in a key-open¬ 
ing airtight can. In use, the solder melted and 
at times bonded the spent cartridge to the 
breech plug, requiring use of a chisel, or caused 
the breech threads to become jammed. 

The improved and final cartridge E7 substi¬ 
tuted a perforated steel basket with crimped 
seams for the soldered copper screen basket de¬ 
scribed above. This was contained in a tinned 


steel sleeve having in. rings at each end 
serving to keep the basket in place. This cart¬ 
ridge eliminated solder troubles, minimized 
leakage of molten residue, and combined better 
strength with ease and cheapness of produc¬ 
tion. 

12,4,4 Breech Plug Cup 

To prevent plugging of the blowdown valve 
(which is at the base of the breech plug), jam¬ 
ming of breech threads by solidification of pre¬ 
viously molten residues, or sticking of spent 
cartridges in the reactor, a breech plug cup 6 
was adopted. 

12 4 5 Water Feed Time 

The water is introduced by gravity from a 
water bottle which holds the recommended 
amount of water when filled to overflowing. 
The size of the water feed valve controls the 
time taken to empty the water bottle. If the 
opening in this valve is too large, the reaction 
will be so rapid that an excessively long air¬ 
cooled coil will be needed to cool the gas to 
within 10 to 20 F of ambient temperature, and 
difficulties with molten residue might be en¬ 
countered. Very slow introduction of water 
limits the number of cycles per hour. Tests 
showed that good results were obtained with 
a water bottle drainage time of 50 to 70 sec, 
obtained with the standard 14 -in. stainless 
angle needle valve used on the E5 generator. 

12,4,6 Cooling Requirements 

During the gas generating period approxi¬ 
mately 1,000 Btu per cycle are absorbed by the 
water jacket. With infrequent cycles, the jacket 
water never boils and makeup water is not re¬ 
quired, but with 4 to 6 cycles per hr a maxi¬ 
mum of 1 lb of jacket water is evaporated in 
each cycle. The bulk of the heat in the gas 
leaving the reactor is removed by three turns 
of helically coiled %-in. OD Monel or Inconel 
tubing submerged in the water jacket, and the 
remainder is removed in nine turns of the same 
coil exposed to air outside the water jacket. 
During the blowdown period a substantial 



76 


HYDROGEN GENERATOR 


amount of heat is present in steam and surplus 
hydrogen gas bled from the blowdown valve 
at the base of the breech plug. A relatively 
large quantity of heat is removed with the spent 
cartridge as sensible heat (molten residue in 
the center of the can at approximately 1,000 
F) and as chemical heat in the residue con¬ 
taining both LiOH and Li 2 0. 

124/7 Cyclone Separator 

Even with the dome at the top of the reactor 
which serves to disengage foam from gas, some 
10 ml of liquid is carried through the coils to 
the top of the water bottle, and is removed by 
the cyclone-type separator in the top of the 
water bottle. The liquid recirculates by gravity 
through the water feed valve. The gas is forced 
to flow through the cooling coils and cyclone 
separator, rather than through the water feed 
line, by installing a vertical U trap (2 in. high) 
in the water feed line. 

12.4.8 Materials of Construction 

At the request of the CWS, mild steel was 
used for the reactor and water bottle, but Monel 
or the equivalent was permitted for the cool¬ 
ing coil, water jacket, and certain small 
threaded parts, and stainless steel was author¬ 
ized for valves. The reactor was designed with 
a wall % 6 in. thick, which includes a corrosion 
allowance of y 16 in.; the outer surface was cop¬ 
per plated in the case of the twenty-five E5 gen¬ 
erators and was zinc plated on the E5R1 gen¬ 
erators. 

12 49 Safety Heads 

The E5R1 contained one replaceable Kidde 
safety head, bursting in the range 2,500 to 
3,000 psi. 

12 410 Pressure Tests 

Both an E5 and an E5R1 generator were 
pressure tested hydraulically. The pressure 
gauge on the generator operated successfully 


after being subjected to a pressure of 4,500 
psi, and the Bourdon tube (in the gauge) rup¬ 
tured at 9,500 psi. Upon blanking off the pres¬ 
sure gauge, the breech enlarged enough at 
10,000 psi to allow the Neoprene breech gasket 
to extrude, releasing the pressure. 

125 POSSIBLE FUTURE IMPROVEMENTS 

At the time of the demonstration of the four 
types of generator at Edgewood in October 
1944, the air-cooled unit shown was not made 
by a standard manufacturing operation, and 
hence the water-cooled unit was adopted. How¬ 
ever, while the E5 and E5R1 developments 
were under way, two air-cooled units were 
developed, involving standard methods of man¬ 
ufacture. The Al-Fin type was prepared by 
casting aluminum alloy around the reactor and 
milling vertical fins, so that air would flow up¬ 
wards between the fins by natural convection 
circulation. The Harrison Radiator type bonded 
copper to the reactor in the form of U-draped 
ribbon. In either event the fins were housed in 
an air jacket connected to a chimney, and the 
gas was cooled in a helical coil wound around 
the chimney. These two air-cooled reactors 
were assembled as experimental generators by 
Artisan Metal Products. Since they became 
available only at the time the project closed, 
they were turned over to the CWS Development 
Laboratory at MIT for testing and further de¬ 
velopment. The Harrison-Artisan air-cooled 
generators weighed approximately 49 pounds 
including the charging line, as compared with 
58 pounds for E5 or E5R1 with full water 
jackets, and did not require cooling water, 
thereby reducing the total maximum water 
consumption of the water-cooled unit by 45 
per cent. 

The alternative development of a gas gener¬ 
ator based on the burning of cordite or double 
base powder was carried to the point of suc¬ 
cessful demonstration of prototype models at 
Allegheny Ballistics Laboratory. The cordite 
generator was not developed far enough to jus¬ 
tify definite conclusions regarding its relative 
merits as compared with the hydride generator, 
and it is possible that a very simple and light¬ 
weight cordite generator could be designed. 



Chapter 13 

INSTANTANEOUS RESPIRATION RATES 


i3.i SUMMARY 

I nstantaneous air flows for inspiration and 
expiration were obtained for a wide range 
of work rates, environmental conditions, res¬ 
piratory resistances, and types of work, by 
means of a new type of instrument. Instan¬ 
taneous inspiration rates as high as 276 liters 
per minute were recorded for men doing heavy 
work. The use of a device simulating human 
breathing was developed for testing protective 
equipment, and the adoption of this technique 
resulted in the rejection of large quantities of 
charcoal found acceptable on the basis of the 
earlier breakdown test at a constant air rate 
of 32 liters per minute. 

Fundamental data on the design, perform¬ 
ance, and testing of outlet valves were obtained. 
Values for maximum allowable resistance for 
inspiration and for expiration were determined 
for medium and heavy work rates. It was 
found that the maximum permissible breathing 
resistances corresponded to breathing work of 
about 1.2 per cent of the external work being 
performed. 

A portable instrument for measuring air 
flow under field conditions was developed and 
used to obtain data on respiration rates of men 
performing various tasks. 


132 INTRODUCTION 

In the early stages of World War II gas mask 
adsorbents and canisters were tested for pro¬ 
tective efficiency and breakdown at a steady air 
flow of 32 liters per minute. Resistance of 
masks, valves, and canisters were evaluated at 
a steady air flow of 85 liters per minute. No 
critical evaluation of respiratory resistance ex¬ 
isted upon which the upper limit for inspira¬ 
tory canister and expiratory valve resistances 
could be specified. 

A first objective was to determine the in¬ 
stantaneous rates of inspiratory air flow with 


subjects performing varying amounts of work. 
In order to obtain these values, it was neces¬ 
sary to use an instrument with negligible lag 
and inertia which would not add any signifi¬ 
cant resistance to breathing. Such a flow meter 
was developed for instantaneous air-flow mea¬ 
surements. 1 ’ 2,6 This instrument consisted of a 
microscopic platinum wire, 10 microns in dia¬ 
meter, suspended across the diameter of a 31.6- 
mm tube. One end of the wire was attached 
to a fine spring. When air flowed through the 
instrument, the displacement of the wire was 
recorded photographically by a moving-film 
camera. The deflection of the wire was linear 
with air flow, and its inertia, lag, and fre¬ 
quency of vibration did not interfere with res¬ 
piratory measurements. 


13 3 INSPIRATORY AIR-FLOW 
DETERMINATIONS 

Studies were made 1 on a large group of sub¬ 
jects under sedentary and working conditions 
with no inspiratory resistance and with 25, 50, 
76, 102, 152, and 203 mm of resistance (re¬ 
sistances were in mm water at 85 liters per 
minute). Work rates of no external load, 179, 
415, 622, and 830 kg-m per minute were em¬ 
ployed. Measurements of inspiratory curves 
and of minute volume were made for each sub¬ 
ject under each condition. The photographic 
records obtained on all subjects were analyzed 
for respiration rate, maximum inspiratory air 
flow, length of inspiratory and expiratory 
cycles, sustained flow (two-thirds of maximum 
flow), flow above 85 liters per minute, and rise 
to sustained flow. 

The data obtained showed that the earlier 
constant-flow standards for rating and testing 
canisters were inadequate. Maximum flows ob¬ 
tained when subjects performed maximum ex¬ 
ertion were several times greater than the 32 
and 85 liters per minute constant-flow test 
rates for canister penetration and breakdown 


77 


78 


INSTANTANEOUS RESPIRATION RATES 


and for resistance rating. It was recommended, 
for tests of canister penetration and break¬ 
down, that a device be employed which simu¬ 
lated human breathing in frequency, amplitude, 
and shape of the inspiratory curves, and such 
a device was constructed. Using this technique, 
acceptance tests of production lots of canister 
charcoal resulted in the rejection of consider¬ 
able quantities which had previously been 
thought to be satisfactory. The technique also 
reversed the order of the life test results with 
certain standard war gases adsorbed on a typi¬ 
cal charcoal. 

Maximum and average inspiratory air flows 
depend upon the amount of work being per¬ 
formed and the inspiratory canister resistance. 
Both of these factors must be taken into con¬ 
sideration in rating and testing protective can¬ 
isters. With the values presented, the maxi¬ 
mum rate of inspiratory flow can be estimated 
from the volume breathed under a wide range 
of conditions. 

An extension of the above study was made 
with strenuous work carried to exhaustion 
under tropical and normal temperatures to ob¬ 
serve the effect of strenuous exercise and tem¬ 
perature on air-flow measurements. Measure¬ 
ments were made on subjects walking and run¬ 
ning on a treadmill with and without field 
equipment. Inspiratory and expiratory flows 
were determined 4 on the same subjects riding 
a bicycle ergometer. The salient findings of 
this study are given below. 

The highest maximum air flows, minute vol¬ 
umes, and respiration rates were produced by 
soldiers carrying full equipment when running 
at 5.6 mph and approaching exhaustion. The 
highest mean values found with 17 subjects 
were 203 liters per minute for maximum in¬ 
stantaneous inspiratory air flow, 82.5 liters for 
minute volume, and 47 respirations per minute. 
The highest individual maximum inspiratory 
air flows occurred in most cases during the 
three minutes just preceding exhaustion. Over 
one-half of these flows occurred in the last min¬ 
ute of running before exhaustion. About 20 
per cent of the subjects had their highest in¬ 
dividual maximum inspiratory air flows during 
recovery, immediately following cessation of 
work. During a single breath, volumes of air 


as high as 1.1 liters with a peak instantaneous 
flow rate above 276 liters per minute were 
recorded. There was no significant difference 
in maximum inspiratory air flows, minute vol¬ 
umes, respiration rates, and shapes of inspira¬ 
tory curves obtained under tropical environ¬ 
mental conditions when compared with those 
for the same subjects under normal environ¬ 
mental conditions. The most significant effect 
of the tropical environment was that it limited 
the endurance of the subject. The mean dura¬ 
tion of the experiments was reduced about 20 
per cent by the tropical environment. 

The effect of increasing the resistance to in¬ 
spiration (from 15 to 72 mm of water at 85 
liters per minute) when the expiratory resis¬ 
tance remained the same (selected M-8 valves, 
23 to 25 mm of water at 119 liters per minute) 
was to reduce the respiration rate (4 to 6 per 
cent), the minute volume (13 per cent), and 
the maximum instantaneous air flow (15 to 19 
per cent). The length of the inspiratory cycle 
and the proportion of the cycle represented by 
the rise to sustained flow were both prolonged 
by the increased resistance. 

No significant effects of a total inspiratory 
resistance of 72 mm (at 85 liters per minute) 
on endurance, pulse rate, body temperature, or 
pulse recovery were observed. It was evident 
from the reported subjective reactions that the 
above resistance was within the permissible 
limit of inspiratory resistance. Only when the 
amount of work performed was at the upper 
limit of the subject’s working capacity did this 
inspiratory resistance perceptibly affect the 
subject’s ability to complete the work. 

One of the most important factors that af¬ 
fect the length of time to attain high maximum 
air flows, minute volumes, and respiration rates 
was the weight of equipment carried by the 
subject. The endurance of the subjects in these 
experiments was approximately halved when 
full equipment was carried. If the work per¬ 
formed was continued to exhaustion, maximum 
air flows of the same order of magnitude were 
obtained whether the subject was or was not 
carrying equipment. 

The effort required during walking on the 
treadmill at 4.3 mph with full equipment re¬ 
sulted in inspiratory air flows equivalent to 



INSPIRATORY AIR-FLOW DETERMINATIONS 


79 


those obtained with a work rate of 1,107 kg-m 
per min on the bicycle ergometer. Running at 
5.6 mph under the same conditions of resistance 
resulted in air flows, minute volumes, and res¬ 
piration rates exceeding those in the bicycle 
ergometer work by 25 per cent for maximum 


spiratory and expiratory air flows, to reduce 
the minute volume and respiration rate, and 
to prolong the phase of the cycle in which the 
resistance was greatest. Usually the inspira¬ 
tory cycle was prolonged. For all practical pur¬ 
poses, when both resistances are present, the 



INSPIRATORY FLOW 


TREADMILL 


INSPIRATORY FLOW 


BICYCLE ERGOMETER 


Figure 1. Respiration curves for men operating a treadmill and bicycle ergometer. 


flow and 40 per cent for minute volume and 
respiration rate. 

The effects of simultaneous inspiratory and 
expiratory resistance were to reduce the in- 


expiratory cycle may be considered to be about 
10 per cent greater than the inspiratory cycle. 

A typical set of air-flow curves is shown in 
the accompanying Figure 1. These illustrations 











80 


INSTANTANEOUS RESPIRATION RATES 


are reproduced from actual records taken dur¬ 
ing the experiments. The curves run from 
left to right. Time intervals are % sec (indi¬ 
cated by notches in horizontal line at top). 
The treadmill curves were taken on a subject 
walking with full equipment at 4.3 mph and 
breathing through a combat service mask. The 
bicycle ergometer curves are for a subject rid¬ 
ing at 1,107 kg-m (8,000 ft-lb) per minute 
and breathing through resistances comparable 
at maximum work. 

13 4 CHARACTERISTICS OF INSPIRA¬ 
TORY AND EXPIRATORY VALVES 

In order to determine the characteristics and 
nature of respiratory resistance of protective 
respiratory equipment, a study was made of 
all existing physiological, industrial, and ser¬ 
vice-mask valves. 2 

A study of 37 valves showed that the most 
important mechanical characteristics of these 
valves are their resistance to air flow, leakage, 
and opening pressure. All these factors were 
found to be related. Other important consid¬ 
erations are the location of the valve in the 
mask and the protection of the valve from 
damage and climatic conditions. 

Comparison of various methods of determin¬ 
ing the resistances of these valves to expira¬ 
tory air flows indicated that the chamber test 
closely simulated the results obtained in tests 
with human subjects while sedentary or work¬ 
ing. In the human tests, the air flow was mea¬ 
sured by a modified instrument of the displaced 
wire type. 

A detailed study was made of the resistance 
of the valves to various air flows, in chamber 
tests, and the data were plotted. The factors 
regulating the resistance to flow for various 
types of valves were analyzed. In these cham¬ 
ber tests, the curves of the resistances of the 
valves to increasing air flows, up to 250 liters 
per minute, were linear or nearly linear in 
many cases. To simulate the characteristics 
of valves in physiological respiration studies, 
a device having a linear relationship of resis¬ 
tance to air flow is recommended. 

Tests of United States and foreign service 
masks showed that the lowest resistance to 


expiratory flow was offered by the Japanese 
army service mask. Modifications of the Jap¬ 
anese expiratory valve were developed which 
offered even less resistance. At a flow rate of 
119 liters per minute, a resistance of less than 
10 mm of water was obtained for a large-sized 
valve, and a resistance of less than 15 mm for 
a smaller valve. Both valves met the leakage 
specifications of the Chemical Warfare Service. 

A new method of determining valve leakage, 
which corresponds closely to actual conditions 
in human respiration, was developed. The re¬ 
sults obtained with this new method were com¬ 
pared with determinations of the static leak¬ 
age of the valves when dry and when wet. 
Tests of leakage of an expiratory valve most 
representative of the conditions obtained dur¬ 
ing human use should be made when the valve 
is wet. The most practical method of express¬ 
ing the valve leakage in these tests, to com¬ 
pare with the leakage under conditions of hu¬ 
man use, was found to be the leakage per res¬ 
piration. 

Three methods of determining opening pres¬ 
sure were applied to expiratory valves, and 
their results were compared. Opening pres¬ 
sures that compared favorably with actual pres¬ 
sures of the valves in human use were those 
obtained when the valves were wet. Determina¬ 
tions of opening pressure, to be of significance, 
should be made with wetted valves. 

13 5 EVALUATION OF MAXIMUM AL¬ 
LOWABLE RESPIRATORY RESISTANCE 

The object of this phase of the project was 
to determine maximum permissible amounts of 
inspiratory and expiratory resistance to breath¬ 
ing under conditions of heavy and medium 
work. The shape of expiratory air-flow curves 
and the relationship of inspiratory and expira¬ 
tory air flows with varying amounts of resis¬ 
tance were observed. In addition, a study of 
the effect of physical condition on respiratory 
performance data was made. 

The following conclusions were made on a 
basis of the data and observations obtained 
under heavy and medium work rates: 

Inspiratory resistances up to 106 mm of 
water at 85 liters per minute and expiratory 





MAXIMUM ALLOWABLE RESPIRATORY RESISTANCE 


81 


resistances up to 76 mm of water at 85 liters 
per minute separately do not interfere with 
the performance or completion of 15 minutes 
of heavy work (830 kg-m or 6,000 ft-lb per 
minute). A combined resistance of 106 mm 
inspiratory and 41 mm expiratory (total 147 
mm) similarly does not hinder performance or 
completion of the above amount of work. 

Physiological and subjective reactions indi¬ 
cated that for the heavy work rate (830 kg-m) 
resistances exceeding 82 mm inspiratory and 
53 mm expiratory are not well tolerated sepa¬ 
rately or combined, although the work can be 
done. It is important to note that these values 
apply to subjects in fair condition without 
training for breathing through resistances. 
With training both for the work rate and for 
the resistance, it is probable that these values 
could be exceeded. 

At maximal work, resistance becomes a more 
important factor. Subjects in good condition 
who can perform 1,107 kg-m (8,000 ft-lb) per 
minute of work for 15 minutes with minimal 
resistance (6 mm inspiratory and 3 mm ex¬ 
piratory) can breathe through resistances of 
64 mm inspiratory and 41 mm expiratory and 
still perform the work without difficulty. Sub¬ 
jective responses indicate, however, that re¬ 
sistances above these amounts would not be 
well tolerated. 

Inspiratory resistance alone above 64 mm 
does not cause so many subjective complaints 
as expiratory resistance alone above 54 mm of 
water. When expiratory resistance alone is 
present, or is greater than inspiratory at heavy 
work rates, oxygen consumption is lowered and 
oxygen debt may result. The addition of in¬ 
spiratory resistance to such a condition in¬ 
creases the oxygen consumption to a value 
compatible with the work rate. Expiratory 
resistance should never exceed inspiratory un¬ 
less both values are minimal. 

Additions or reductions of 10 to 20 mm of 
water to either inspiratory or expiratory re¬ 
sistance will not produce any significant change 
in physiological or subjective reactions at heavy 
or medium work rates as long as the resistance 
is maintained within the limits stated above. 

The results obtained at a medium work rate 
(415 kg-m or 3,000 ft-lb per minute) confirm 


the observations made at heavier work rates 
with the exception that higher resistance can 
be tolerated at the lower rate. This work rate 
can be maintained for over eight hours. 

Individual variations were considerable for 
each resistance condition. The majority of the 
subjects, however, showed a decreased minute 
volume and a decreased respiration rate as res¬ 
piratory resistance was increased. To compen¬ 
sate for these reductions, the oxygen deficit 
was increased, thus maintaining the required 
oxygen consumption for the work rate. The 
physiological mechanisms can apparently com¬ 
pensate for large changes in resistance by ad¬ 
justing respiration rates, shapes of air-flow 
curves, and gas exchange values to maintain 
oxygen consumption. 

Subjective reactions did not show correlation 
with objective measurements at resistance val¬ 
ues of 64 mm of water at 85 liters per minute 
inspiratory and 41 mm of water at 85 liters 
per minute expiratory, which were comparable 
or somewhat greater than for the current ser¬ 
vice equipment. When the resistance is in¬ 
creased above these values, the number of com¬ 
plaints evoked was in proportion to the amount 
of inspiratory or expiratory resistance. Sub¬ 
jective responses are not a satisfactory cri¬ 
terion of physiological reactions to resistance 
unless the amounts of resistance exceed the 
limits stated previously. 

Mean respiratory work rates formed only 
a small percentage of the total external work 
even when resistances of 106 mm inspiratory 
and 41 mm expiratory were present and a high 
percentage of subjective complaints were 
evoked. Respiratory work rate expressed as a 
percentage of the total external work may form 
a convenient basis for expressing permissible 
limits of resistance to respiration, since flow, 
resistance, and the external work rate are in¬ 
cluded. This study indicated that 1.2 per cent, 
corresponding, at a heavy work rate (830 
kg-m), to 82 mm inspiratory and 53 mm ex¬ 
piratory resistances, is a reasonable limit of 
respiratory work which will not cause an ap¬ 
preciable number of objections to breathing 
through the resistance. Thus the allowable re¬ 
sistance for a given work rate can be deter- 



82 


INSTANTANEOUS RESPIRATION RATES 


mined from the minute volume, per cent of 
cycle values, and external work rate. 

Observations on the subjects performing the 
experiments indicated that a practical rather 
than a physiological limit should be used for 
expiratory valve resistance in gas masks, since 
the resistance at which the face piece tends 
to “valve off” is below those found physiologi¬ 
cally undesirable. The expiratory resistance 
should be low enough to prevent valving off 
when the suspension is adjusted so that the 
face piece fit is leakproof but the suspension 
tension is not so tight as to be uncomfortable. 
The lower the amount of expiratory resistance, 
the more readily this condition is attained. 

Good physical condition resulted in superior 
performance of heavy work. A comparison of 
athletes and non-athletes of the same age group, 
each performing bicycle ergometer work with¬ 
out previous ergometer experience, showed the 
athletes to be much better than the non-athletes. 
The outstanding differences shown by the ath¬ 
letes were a lower working pulse rate, a lower 
minute volume, lower maximum flows, de¬ 
creased oxygen consumption, and an increased 
oxygen deficit. 

Test-retest values correlated well indicating 
that there was not any significant training ef¬ 
fect in these experiments. The coefficients had 
high values, which checks the reliability of the 
measurements. Good correlations were found 
between oxygen consumption and pulse rate. 
The correlation of these two values was re¬ 
duced significantly when expiratory resistance 
was present, possibly indicating some effect of 
expiratory resistance on the circulation. 

The mean data obtained indicated that oxy¬ 
gen deficit, respiration rate, and minute-volume 
changes are a function of total resistance. As 
the total resistance (inspiratory plus expira¬ 
tory) increased, oxygen deficit increased, and 
respiration rate and minute volume both de¬ 
creased. When the resistances were above mini¬ 
mal values, the maximum air flows, air-flow 
curve proportions and shapes, and flow ratios 
were in proportion to the ratio of inspiratory 
to expiratory resistance. Pulse rate changes 
were not significantly altered by resistance. 
They were, however, affected materially by 
physical condition and adaptation to work. 


Protective respiratory equipment employing 
resistances which exceed the limits found in 
this study should be modified so as to reduce 
their resistance within the desirable limits. 
Suggested maximum limits are 82 mm of water 
at 85 liters per minute for inspiration and 58 
mm of water at 85 liters per minute for ex¬ 
piration. 

Expiratory resistance should never exceed 
inspiratory in any protective equipment unless 
both amounts are minimal. Rebreathing de¬ 
vices should be designed so that they do not 
require exhalation through resistance (carbon 
dioxide removal canister), but rather that the 
air to be purified should be drawn through the 
canister during inspiration. 

The effect of training on performance of 
subjects breathing through resistance deserves 
further investigation. General physical train¬ 
ing will reduce air-flow requirements for a 
given work rate considerably (20 per cent). It 
is probable that training with resistance will 
decrease air-flow requirements and also permit 
higher resistances to be used for greater pro¬ 
tection. 

The data presented on the effect of inspira¬ 
tory and expiratory resistance on the shape of 
the air-flow curves and maximum air flows can 
be applied to the design of simulated breathing 
devices and valves for protective equipment. 

The question of subjective reactions to resis¬ 
tance was studied in a short investigation. 3 
Service masks with the canisters mounted on 
the face pieces (combat) and service masks 
with canisters in carriers were studied. Sol¬ 
diers had reported that service masks with the 
canisters mounted on the face pieces had lower 
resistance, but at steady test air flows this 
difference did not exist. Measurements were 
made with static (steady) and dynamic (simu¬ 
lated breathing) air flows to see whether the 
reported differences were due to dynamic air 
movements. No difference was found. 


136 FIELD STUDIES 

In conjunction with the work on inspiratory 
air-flow determination, a portable air-flow mea¬ 
suring instrument was developed. 5 By means 



FUTURE WORK 


83 


of this instrument it was possible to make air¬ 
flow measurements of soldiers performing vari¬ 
ous field operations. A preliminary study of 
coast artillery, obstacle course, and tank opera¬ 
tions was made. 7 The data obtained on field 
studies are of value in estimating requirements 
and life of protective respiratory equipment. 

13 -7 FUTURE WORK 

The measurements of inspiratory flow and 
their magnitude indicate that some develop¬ 
ment might be directed towards use of devices 
to mechanically reduce the peak flow of air. 


It was also observed that training and physical 
condition have an important effect upon the 
volume of air breathed and the maximum air 
flows which result when moderate to exhaust¬ 
ing work is performed. Further study on the 
effects of training on air flow and tolerance to 
resistance is needed. The study made on this 
project indicates that subjective reaction to re¬ 
sistance can be materially reduced by training 
or gradual acclimation to increasing amounts 
of resistance. 

The study of air-flow requirements for vari¬ 
ous field operations should be continued in or¬ 
der to determine the amount of protection 
needed and the life of the protective device. 


mmwmmmM 




Chapter 14 

SABOTAGE OF GASOLINE ENGINES 


B ecause of the extensive mechanization of 
warfare, there is a continual requirement 
for effective methods of causing gasoline en¬ 
gines to become inoperative, either in order to 
immobilize combat vehicles or to disrupt move¬ 
ment of supplies. 

141 PROKNOCKS 

Since the discovery made during World War 
I that small amounts of certain compounds 
added to gasoline, or admitted through the car¬ 
buretor air stream, would make a motor knock 
with resulting loss of power, many suggestions 
were made that such materials be put to mili¬ 
tary use as a means of impeding enemy activ¬ 
ity. These suggestions have ranged from creat¬ 
ing gas clouds in front of attacking airplanes 
to adding a proknock to gasoline for sabotage 
purposes. Outstanding among these sugges¬ 
tions was the proposed use of the latter agent 
for immobilizing planes at the time of take-off 
from enemy fields. 

This investigation was started by measuring 
the effectiveness of all varieties of available 
compounds, with particular reference to those 
previously reported as showing promise. All 
compounds showing even slight activity were 
found to contain one or more of the following 
elements: nitrogen, phosphorus, arsenic, anti¬ 
mony, oxygen, sulfur, chlorine, bromine, and 
mercury. It further became apparent that com¬ 
pounds consisting exclusively of these elements 
showed, in general, stronger action than com¬ 
pounds containing other elements in addition. 

All tests were made in a standard CFR knock 
test engine using the American Society of Test¬ 
ing Materials method (ASTM D 357-40). The 
principal fuels used were non-leaded base for 
100 -octane aviation gasoline and the same base 
treated with approximately 2.8-cc tetraethyl 
lead in ethyl aviation fluid. In some tests the 
materials were added to blends of benzol and 
a straight run gasoline of low octane number 
treated with several concentrations of lead. 


Approximately 250 materials were tested in 
varying concentrations with one or more of 
these fuels. 2 The materials were introduced 
into the engine in solution in the fuel, in a 
solvent in solution in the fuel, in solution in 
a solvent introduced into the air intake system, 
as solids delivered at the intake valve, or as 
a vapor or gas introduced into the air intake 
system. In most cases the method used was 
dependent upon the characteristics of the ma¬ 
terial being tested, though some comparisons 
of methods were made. 

Many of the materials tested had little or no 
effect on the antiknock value of either un¬ 
treated fuels or fuels treated with tetraethyl 
lead. Some materials greatly reduced the oc¬ 
tane number of both leaded and non-leaded 
gasolines, while others reduced the octane num¬ 
ber of leaded gasolines only. A few materials 
reduced the antiknock value of untreated fuel 
without appreciably changing the value of leaded 



Figure 1. Test results of proknock materials. 


gasoline, and in a few instances materials were 
knock suppressors in the untreated fuel but 
induced knock in the treated gasoline. Typical 
experimental data are shown in Figure 1. 


84 









GASOLINE SABOTAGE 


85 


The most effective materials found are listed 
below. The concentration given is the amount 
of material required to reduce the antiknock 
value of the fuel by 12-octane units. 

Concentration, parts of 
material per million 
parts of air to effect a 
reduction of twelve in 
octane number 


Material 

By weight 

By volume 

In Lead-Treated Fuel 



White phosphorus 

6.4 


Nitrogen chloride 

29 

7 

n-Butyl dichlorophosphine 

44 

8 

Arsenic trichloride 

49 

8 

Arsenious acid anhydride 

50 

8 

Sulfur trioxide 

60 

22 

Sulfur dichloride 

62 

18 

Sulfur monochloride 

68 

15 

1,1 -Dichloro-1 -nitroethane 

72 

15 

1-Chloro-l-nitropropane 

80 

19 

Phosphorus sulfochloride 

85 

15 

Phosphorus trichloride 

87 

19 

Ethyl thionitrite 

88 

29 

FS (55% sulfur trioxide, 45% 



chlorosulfonic acid) 

90 


Nitrosyl chloride 

95 

42 

In Non-Leaded Fuel 



Nitrogen chloride 

148 

36 

2-Ethylhexyl nitrite and chloro- 



picrin* 

270 

48 

2-Ethylhexyl nitrite 

290 

53 

Chloropicrin and isoamyl nitrite* 

317 

62 

2-Chloroethyl nitrite 

365 

97 

Isoamyl nitrite 

500 

123 

Chloroform and isoamyl nitrite* 

550 

134 

Isoamyl nitrite and n-butyl sulfide* 

550 

122 

Amyl nitrate 

620 

135 

Chloropicrin, isoamyl nitrite, and 



n-butyl sulfide* 

620 

121 

Isoamyl nitrate and n-butyl sul¬ 



fide* 

680 

141 

Isoamyl nitrate 

700 

153 

n-Butyl sulfide and chloropicrin* 

720 

132 

Tertiary butyl thionitrite 

750 

182 


* Equal parts of each component. 


The effectiveness of any of these materials 
will depend on how they are used. For overall 
value, nitrogen chloride proved itself the strong¬ 
est proknock. All other agents tested varied 
their relative effectiveness with the type of 
fuel and their concentrations. Hence to select 
the most suitable substitute for nitrogen 
chloride, it is necessary to decide in advance 
the optimum concentration and to know the 
type of fuel being used by the enemy. Nitro¬ 
gen chloride has the disadvantage of being dif¬ 
ficult to handle because of its instability. It 


decomposes slowly even at the freezing point, 
and it explodes at 201 F or on contact with 
some organic materials. 

The obvious disadvantages of the use of a 
proknock material for dispersal on enemy air 
fields to prevent take-off of planes are: 

1. The quantities required to create effective 
gas clouds are excessive. (The concentration 
of 29 ppm by weight required to reduce the 
octane rating 12 units corresponds to 300 
pounds of agent uniformly dispersed in the air 
to a depth of 50 ft over an area of 1 square 
mile.) It was decided that the same weight 
of high explosive would be more effective. 

2. Air movements of even moderate propor¬ 
tions will rapidly dissipate gas clouds and 
hence cause the effectiveness to be only transi¬ 
tory, requiring no effort on the part of the 
enemy for its removal. 

3. Any effectiveness disappears at part throt¬ 
tle, or low barometric operation of motorized 
equipment. This must be taken into account 
when considering warfare against tanks and 
aircraft at high altitudes. No data were ob¬ 
tained on whether the octane number reduction 
which could be obtained was sufficient to pre¬ 
vent take-off of planes. 

Tests were made to determine the effect on 
a Plymouth engine of reducing the octane num¬ 
ber of the fuel. The engine was adjusted for 
a trace knock at 1,200 rpm and full throttle 
using 70-octane fuel. Other fuels were blended 
to give 60-, 50-, and 40-octane number and were 
substituted for the 70-octane fuel. The 60- and 
50-octane fuels caused knocking, but did no 
damage to the engine in 5 minutes of operation. 
Forty-octane fuel caused extremely heavy 
knocking. The engine was operated for 20 
minutes, which is far longer than an engine 
in such distress would be driven under ordi¬ 
nary circumstances. No damage was done and 
the observed blow-by was constant during this 
time. These tests indicate the futility of try¬ 
ing to destroy an automotive engine by lower¬ 
ing the octane rating of the fuel. 

142 GASOLINE SABOTAGE 8 

At the time of the German drive through 
Holland, Belgium, and France in 1940, large 




86 


SABOTAGE OF GASOLINE ENGINES 


quantities of gasoline were abandoned and used 
by the Germans. Because of storage conditions, 
particularly underground storage, it was very 
difficult to sabotage these supplies with ex¬ 
plosives or incendiaries, and a request was 
made for a contaminant which could be added 
to the fuel to make it unfit for use. As the 
Allies changed from the defensive to the of¬ 
fensive, the requirement changed from sabo¬ 
tage of “friendly” gasoline to that of “enemy” 
gasoline. The use visualized also changed from 
sabotage of bulk supplies to sabotage of drum 
lots, or the fuel of individual vehicles. These 
changes, however, did not appreciably alter the 
desired properties of the material sought. The 
specifications for the ideal material were that 
it be nondetectable and a small quantity be 
required, that it ruin any engine, that it mix 
with the fuel automatically, and that it work 
in all types of gasoline. 

The best material found was an oil-soluble 
phenolic resin made by condensing a para- 
tertiary alkyphenol with formaldehyde. This 
product is sold by the Paramet Chemical Cor¬ 
poration and is known as Paradura 10-P. It 
is a solid and heavier than gasoline but readily 
soluble, and is not easily detectable after solu¬ 
tion. It should be prepared as fine aerated 
granules which will float on gasoline. It can 
be used as a 50 per cent solution in gasoline, 
but this increases the weight of material to 
handle. The Paradura was deposited on the 
valves and valve stems of a running motor, 
causing sticking of the valves. When one-half 
gallon of fuel containing 20 grams per gallon 
was passed through each cylinder of a motor, 
the intake valves began to stick open and the 
motor missed badly. When the motor was 
stopped, it could not be restarted. Continued 
use resulted in stalling of the motor. 

Other effective compounds in the order of 
their effectiveness were: 

1. Soluble phenolic resins. 

a. Paradura No. 367. 

b. Super Beckacite No. 1001. 

2. Rosin ester (ester gum), or Santoresin. 

3. Chinawood oil. 

4. Phosphorus trichloride or phosphorus di- 
chloronitride (PNC1 2 ). 


Twenty grams per gallon is an effective con¬ 
centration for these materials. Ten grams can 
be used, but twice or more the running time is 
necessary. The phosphorus compounds caused 
sticking of the piston rings; the others pri¬ 
marily caused valve sticking. 

Over 225 compounds were evaluated in one- 
cylinder air-cooled Delco motor-generator units, 
using 1 quart of treated gasoline for each run. 
The materials showing any appreciable effect 
were given longer tests, using several gallons 
of fuel. The best of these were then checked 
in block tests with a multi-cylinder motor, using 
6 gallons of fuel for each run, and a final check 
was made by a road test using a 1 1 / 2 -ton Ford 
truck. 


143 SABOTAGE OF LUBRICATING OIL 

Methods of sabotaging motor vehicles by ad¬ 
ditives to the lubricating oil were investigated 
in the hope of finding a material which was 
more effective than the fuel additives. Several 
materials were tested which caused severe 
sticking of the engines. The reaction product 
of m-benzenedisulfonic acid and mesityl oxide, 
when added in concentrations of 1 to 2 per cent 
by volume to lubricating oils of the high vis¬ 
cosity index, nonadditive type, caused engines 
to stick so tightly from varnish as to be inop¬ 
erative. 10 In concentrations of 2 to 4 per cent 
it was effective also in oils containing additives 
of the detergent type. When this material was 
poured directly into the crankcase of an engine, 
it caused the engine to seize tight after being 
driven only a few miles. 

The mesityl compound was prepared by dis¬ 
solving, with stirring, 100 grams of m-benzene¬ 
disulfonic acid in 150 cc of mesityl oxide. Cool¬ 
ing was required to keep the temperature at 65 
to 70 C, which should not be exceeded. This 
reaction product is very viscous and difficult 
to dissolve in lubricating oil; before use it 
should be thinned with 40 per cent acetone. 
A slow reaction with the acetone occurs, which 
increases the viscosity so that the thinning 
should be done within a few days of intended 
use. 


^wymyivTiAi £ 



SABOTAGE OF LUBRICATING OIL 


87 


Other agents found effective were: 

Reaction product of acetone and benzenedi- 
sulfonic acid. 

Benzenedisulfonic acid and aldol (added sep¬ 
arately) . 

Benzenedisulfonic acid and crotonaldehyde 
(added separately). 

Furfuryl alcohol. 

A compound labeled RX furnished by Tide¬ 
water Oil Company (composition un¬ 
known) . 


A mixture of the following composition: 9 


Phosphorus 
Linseed oil acids 
Rubber 
Ethyl iodide 
Carbon disulfide 


14.7 per cent 

63.5 “ “ 

2.5 “ “ 

3.5 “ “ 

15.7 “ “ 


Additional work on sabotage of fuels and 
lubricating oils was carried out at the request 
of Division 19. The results are reported in the 
History of Division 19, dated June 30, 1945. 



Chapter 15 

PRODUCTION OF POTABLE WATER FROM SEA WATER 


151 INTRODUCTION 

D rinking water is essential for all military 
operations and often the only available 
source is sea water. Various types of distillers 
had been used for shipboard use but these were 
too cumbersome and hazardous to use on life 
rafts. Only a few days supply of water could 
be carried on the inflatable rafts used by avi¬ 
ators forced down on the ocean, and often this 
was not sufficient for the men to survive until 
rescued. An investigation was, therefore, un¬ 
dertaken for the development of methods of 
obtaining potable water from sea water either 
by distillation or by chemical methods. Chemi¬ 
cal and electrolytic methods for purification of 
water were also investigated as of possible 
application to shipboard use in preference to 
distillation. 

15 2 ELECTROLYTIC METHOD 

The electrolytic method depended on attract¬ 
ing cations and anions toward electrodes sepa¬ 
rated from the water to be purified by perme¬ 
able membranes. This method had been found 
impractical mainly because of the ohmic re¬ 
sistance of ordinary fresh water. However, it 
seemed possible that a combination of new re¬ 
agents with electrolysis might be worked out 
for sea water. The plan was to partially purify 
water by the ordinary electrolytic method and 
then recover the acid and base formed in the 
electrode compartments for use in regenerating 
exchange materials to be used for the removal 
of the remaining solids in the water. The elec¬ 
trolysis operation was not satisfactory, how¬ 
ever, because of back diffusion through the 
membranes. Only about 1 per cent reduction of 
total solids was accomplished. 

153 CHEMICAL METHODS 12 

All the commercially available base exchange 
materials were investigated for their effective¬ 


ness in removing salts from sea water. These 
included Zeo Karb H, Catex, Amberlite IR-1, 
Alkalex, Deacidite, Anex, and Amberlite IR-4. 
Base exchange materials are solid substances 
which react with ions in solution, with the re¬ 
sultant removal of the ions to the solid sub¬ 
stances, the ion being replaced in solution by 
another ion originally on the solid. The most 
efficient cation exchanger found was Amberlite 
IR-1 supplied by Resinous Products Company. 
This material had a capacity of 1.36 milli- 
equivalents per gram. The best anion exchanger 
was Amberlite IR-4 from the same producer, 
which had a capacity of 4.7 milliequivalents per 
gram. After these materials are exhausted 
the cation exchanger can be regenerated with 
sodium hydroxide, the anion exchanger with 
sulfuric acid. The regenerating chemical can 
be dissolved in sea water and the sea water 
used for washing the resin. Using the sea 
water for regeneration reduces the efficiency of 
the exchanger, but this was taken into account 
in the figures given above. It was found pos¬ 
sible to produce water of essentially zero min¬ 
eral content by the use of these resinous ex¬ 
change materials. The necessary filter beds 
and other equipment for a shipboard installa¬ 
tion would weigh about 1 pound per gallon per 
day. This is the same as the installed weight 
of the standard double effect evaporators. How¬ 
ever, for 1 gallon of water obtained, the re¬ 
generation of the exchange resins would require 
1.25 pounds sulfuric acid for the removal of the 
cations and 0.4 pound sodium hydroxide for 
the removal of the anions. The total weight of 
chemical necessary, therefore, for the purifica¬ 
tion of sea water using the exchange resins is 
about 1.65 pounds per gallon as compared with 
0.35 pound fuel oil per gallon of distilled water 
required by the double effect evaporators. It 
was concluded that the chemical methods stud¬ 
ied could not compete with the double effect 
evaporators for shipboard operation. 

The use of heavy metal oxides for the re¬ 
moval of chlorides from sea water was also 


88 


SOLAR STILLS 


89 


investigated. Mercurous oxide removes chlo¬ 
ride from solutions and the precipitated mer¬ 
curous chloride can be converted to the oxide 
with sodium hydroxide. The reaction of the 
mercurous oxide with chloride was practically 
complete; when the theoretical amount of oxide 
was added, only a trace of chloride and mer¬ 
cury were left in solution. This reaction took 
place only in an acid solution, however, and 
was of no value in neutral sea water. The use 
of exchange resins to produce acidity in the sea 
water before treatment with mercurous oxide 
was unsuccessful. Silver oxide precipitated the 
chloride in a neutral solution, but an excess of 
the reagent was required and the reaction was 
slower than with mercurous oxide. Lead oxide 
removed only about 25 per cent of the chlo¬ 
rides. None of these reactions were considered 
satisfactory for use. 

Although the exchange resins were not con¬ 
sidered satisfactory for shipboard use, several 
modifications were developed which might be 
of value on life rafts where regeneration of the 
chemical is not desired. The best of these in¬ 
volved the use of barium to precipitate the sul¬ 
fate. Because of the toxicity of barium, it is 
desirable to use less than the theoretical amount 
for precipitation of all of the sulfate. This 
would insure no barium being left in the water, 
and the small amount of sulfate remaining 
would not be harmful. The solution was then 
filtered and treated with a slight excess of 
Amberlite IR-1, which had been previously 
treated with silver nitrate. The cations were 
taken up by the exchange material and the sil¬ 
ver ions freed to precipitate the chloride from 
the sea water as insoluble silver chloride. The 
solution was then filtered yielding a water with 
a total mineral content of 200 ppm. The ratio 
of water formed to materials used was 6 to 1 
by weight. Thus, six times as much drinking 
water could be obtained by using this chemical 
as could be carried. 

15 4 SOLAR STILLS 4 

The amount of solar energy received on a 
horizontal surface on a clear summer day, or 
average tropical day, averages at least 2,000 
Btu per sq ft. In a simple distillation process 


operating at atmospheric pressure, about 1,100 
Btu are required per pound of distilled water. 
Therefore, if the solar energy could be utilized 
completely for simple distillation, the average 
distilled water obtained would be 1.8 pounds of 
water per sq ft per day. Numerous attempts 
have been made to use solar energy for distilla¬ 
tion. The basis of all solar distillers consists of 
a boiler or evaporator which is a blackened pan, 
or receptacle, containing the feed water. Since 
the evaporator serves the purpose of absorb¬ 
ing solar radiation, it should present an ex¬ 
tended black surface which does not fade in 
color under operating conditions. Its heat ca¬ 
pacity should be small in comparison with the 
heat capacity of the feed water for one day’s 
operation. The condenser consists of an in¬ 
clined surface which transmits solar radiation 
as fully as possible. The condensing surface 
may advantageously surround the evaporator 
on all sides terminating in a collective device 
to accumulate the distillate. In operation the 
absorbed solar radiation heats the feed water 
held in the evaporator. Water vapor is gen¬ 
erated which in turn condenses on the inner 
surfaces of the condenser and is collected by 
suitable means. The process obviously occurs 
at temperatures well below the boiling point 
of water and depends on the diffusion of water 
vapor, through air, from the evaporator to the 
condenser. The condenser surface is inclined 
to facilitate the flow of the condensate. 

Certain losses in the operation of a solar dis¬ 
tiller are unavoidable. Clear glass and most 
transparent plastics suitable for use as the 
condenser absorb a few per cent of the inci¬ 
dent radiation, and about 8 per cent is lost 
from reflectivity, giving a total loss of about 
10 per cent. Film-type water condensation on 
the inside of the surface does not lower the 
transmission of the radiation and is preferable 
to dropwise condensation. Heat losses by re¬ 
flection at the evaporator-absorber surface may 
be caused by imperfect blackness. Surfaces 
showing a flat black finish absorb about 96 per 
cent of the incident solar radiation. The sur¬ 
face of the absorber emits long infrared radia¬ 
tion corresponding to its temperature. Calcula¬ 
tion shows that this heat loss may amount to 
about 12 per cent of the original figure. Heat 





90 


PRODUCTION OF POTABLE WATER FROM SEA WATER 


loss from the evaporator absorber due to dry 
air circulation is relatively small, generally not 
more than 5 per cent of the incident energy 
for most arrangements of the surfaces. The 
heat loss from the bottom side of the evapora¬ 
tor constitutes the most variable factor. This 
loss was a major cause of the low efficiency of 
early solar distillers. The trays containing the 
feed water were made of wood painted black and 
generally placed upon the ground. The thermal 
conductivity of wood is comparatively high 
and a relatively large amount of solar heat was 
wasted in heating the ground. Placing the tray 
upon thermal insulation equivalent to about 
1 in. of insulating board diminishes the bottom 
heat loss to about 10 per cent of the initially 
incident energy. Instead of the insulating 
board, its insulating equivalent of other ma¬ 
terials, or layer-built structures with air spaces, 
may be used and would be preferred from the 
point of view of compactness. The above losses 
indicate that this type of solar distiller should 
show a maximum efficiency near 60 per cent. 

For use on life rafts compactness of the 
packed still is esssential. In order to accom¬ 
plish this compactness, a still was designed 
which was made entirely of flexible, foldable 
materials. This enabled the still to be folded 
into a very compact package but when opened 
up it could be inflated to retain the desired shape 
and size for the practical production of drink¬ 
ing water from sea water. The outer envelope 
of the still designed was made from a trans¬ 
parent vinylite plastic, which, when inflated, 
had a circular pillow shape. The inner surface 
of this plastic envelope served as the condens¬ 
ing surface for the water vapor. On the bottom 
side the envelope was equipped with a water¬ 
collecting bag into which the distilled water 
drained. An outlet was attached to the water 
bag which could be closed with a plug. Inside 
the plastic envelope a black absorbent pad was 
held in a horizontal position by waterproofed 
fabric strips. This pad was made from a re¬ 
generated cellulose sponge containing a per¬ 
manent black dye. 

For operation, the folded still was removed 
from its container and unfolded. A collapsible 
funnel, which was part of the equipment, was 
inserted into the outlet and the still filled with 


sea water through the funnel, to saturate the 
black absorbent pad. The funnel was removed 
and the device inflated through the rubber out¬ 
let, either by mouth, or by means of an air 
pump. The inflated still was closed with the 
plug and the device turned into position with 
the water-collecting bag on the bottom. The 
excess sea water was permitted to drain for 
about 10 minutes, collecting in the water bag 
from which it was removed by temporarily 
opening the plug. The device was then ready 
for operation. It was designed to float in the 
water beside the raft, needing no attention 
except for the removal of the drinking water 
from time to time. When the device was ex¬ 
posed to the sun, most of the solar radiation 
was transmitted by the transparent envelope 
and absorbed by the black absorbent pad, heat¬ 
ing the sea water with which the absorbent pad 
was saturated. Water vapor was generated, 
condensing on the inner surfaces of the en¬ 
velope, which was cooled by the air on the 
upper surface and by the water on the lower 
surface. The condensed distilled water trickled 
down the inner side, collecting in the water bag. 
A slit opening above the center of the water 
bag acted as a valve and prevented the collected 
distilled water from being splashed back into 
the distilling compartment. 

The final model a which was designed had a 
black absorbent pad of 2-sq ft area. When ex¬ 
posed to bright sunshine, the still produced 
about 4 oz of water per hour with a probable 
tropical daily yield of 1 quart of drinking 
water. The folded volume of this model was 
about 70 cu in. (1.2 quarts), including the fold¬ 
ing funnel and the carrying bag, and its weight 
was about 1 pound. 

The inner side of the transparent envelope 
should be coated with an agent which pro¬ 
duces film-type condensation of the water 
vapor. Dropwise condensation absorbs part of 
the energy striking the surface, which results 
in less heat being transmitted to the absorbing 
pad and also causes some revaporization of the 

a The basic development of the still described above 
was completed by the contractor prior to the initiation 
of the OSRD contract. OSRD suggested financing the 
manufacture of a number of prototype models for tests 
by the Services. 




HAND-OPERATED VAPOR COMPRESSION STILL 


91 


condensed water, resulting in a lower yield. A 
good anti-fogging coating was obtained by 
spraying or brushing over the vinylite film a 
solution containing 15 per cent, by weight, of 
polyvinyl alcohol dissolved in a solvent of equal 
volumes of water and alcohol. To produce bet¬ 
ter adhesion, the solution was mixed with about 
10 per cent of acetone or similar solvents, ca¬ 
pable of leaving vinylite slightly tacky. After 
drying, the sheet was baked at 180 to 200 F 
for a short time. Coatings of this kind were 
used in continuous operation for two months 
without showing any deterioration. 

In tests run off the shore of Miami, Florida, 
these stills operated at an efficiency of 49 per 
cent. Figure 1, taken at the time of the Miami 



Figure 1. Two solar stills being operated from 
a life raft. 

tests, shows two inflated stills being operated 
from a raft. Stills of this type were adopted 
by the Army as part of the life raft equipment. 

155 HAND-OPERATED VAPOR 

COMPRESSION STILL 3 

The vapor compression type of still has been 
used with satisfactory results by the Navy for 
shipboard use and by the Army for land use. 
This type of unit has a very high thermal ef¬ 
ficiency, achieved through continual re-use of 


the heat required for vaporization of the sea 
water by efficient heat exchange between in¬ 
coming and outgoing streams. A compressor 
compresses all the steam from the boiling sec¬ 
tion of the evaporator and discharges it at an 
increase of IV 2 to 3 psi to the condensing sec¬ 
tion of the condenser. This pressure differen¬ 
tial serves to raise the condensation tempera¬ 
ture of the steam in the condenser sufficiently 
above the boiling point of the water in the 
evaporator, so that the heat of condensation 
will be transferred to the boiling sea water and 
thereby supply the heat of vaporization for the 
latter. If it were not for loss of heat to the 
surroundings and loss of heat in the streams of 
product and concentrated overflow, only a very 
small amount of power would be required for 
operation of the steam compressor. Even with 
these heat losses the ratio between product out¬ 
put and energy input is quite large; the actual 
energy input as work is of the order of 5 per 
cent of the latent heat of evaporation. 

Because of the high efficiency of this type of 
unit, a model was designed and built which 
utilized the energy input from manual opera¬ 
tion, and which was small enough and light 
enough to be carried on lifeboats and possibly 
on the large inflatable life rafts. The still de¬ 
veloped was 10 in. in diameter and 12 in. high 
and weighed I 7 V 2 pounds without fuel. It pro¬ 
duced distilled water at the rate of 1 pound 
per hour when supplementing the mechanical 
energy input with a small amount of heat. 
With mechanical input alone, the production 
was reduced to about % pound per hour. The 
starting time was 1 hour when the mechanical 
input was supplemented with heat and was 
about 2 hours when no supplementary heat was 
used. By use of heat alone the unit was brought 
to operating temperature in about 1% hours. 
The amount of manual effort required for pro¬ 
duction of a pound of water was very much 
less when supplementary heat was used. When 
using supplementary fuel, the preferred rate 
of fuel consumption was found to be of the 
order of 1 pound for each 57 pounds of water 
produced (based on the use of methyl alcohol 
as fuel). The mechanical energy was supplied 
by means of a manually operated crank at the 
top of the unit. 









Chapter 16 

UNDERWATER COATINGS 


SUMMARY 

C omplete coating systems for Navy vessels 
were investigated by means of laboratory 
studies, submerged panel tests, and trial ap¬ 
plications to vessels of various sizes. Applica¬ 
tion of sand to partially dry primer was found 
to provide a good anchor for the topcoat, and 
to improve adherence of topcoat to primer. A 
wash of phosphoric acid and polyvinyl resins 
in a dilute alcoholic solution provided an ex¬ 
cellent pretreatment of clean steel, and im¬ 
proved adherence of the primer. Both wet 
sand blasting and a special mechanical tool 
were found satisfactory in cleaning ships’ hulls 
prior to painting. 

An improved primer was developed contain¬ 
ing polyvinyl butyral resin pigmented with 
zinc tetroxychromate. This was found marked¬ 
ly to reduce blistering. Blistering was found to 
be due to osmosis caused by increased hydroxyl 
ion concentration resulting from corrosion of 
the steel underneath coatings. Various parts 
of a ship’s hull may be anodic and parts 
cathodic—corrosion occurs on the anodic 
areas and blistering where the surface is 
cathodic. Laboratory techniques were devel¬ 
oped for studying potential changes of corrod¬ 
ing areas, and for measurement of the electri¬ 
cal resistance of coatings. The latter were es¬ 
pecially valuable in indicating tendencies to 
blister. 

A great many antifouling coating formula¬ 
tions were investigated, and the mechanism 
of fouling protection studied in the laboratory. 
A technique of measuring the rate of leaching 
of the toxic copper constituent from the coat¬ 
ing by sea water was developed, and it was 
established that fouling protection was obtained 
if the leaching rate was greater than 8.2 mg 
copper per 24 hours from 1,000 sq cm. The 
other principal variable affecting fouling pro¬ 
tection was the extent and character of the 
insoluble green copper complex deposited on 
the surface after immersion in sea water. Im¬ 


proved antifouling coatings were developed 
containing cuprous oxide, rosin, and vinyl 
resins. These permitted the use of 4 to 5 parts 
pigment to 1 part binder, and gave excellent 
antifouling protection for more than 18 months. 
A new formulation employing flake copper in 
place of cuprous oxide found considerable ap¬ 
plication for wood hulls. 

A study of paint removers showed that 
several formulations based on methylene 
chloride were effective, and were noninflam¬ 
mable as compared with the common acetone- 
benzene mixture. 

Anaerobic sulfate-reducing bacteria were 
found to play an important role in marine 
corrosion, causing the formation of black iron 
sulfide next to the steel. Bacteria were also 
found to attack coatings, and a preliminary 
study indicated that certain paint constituents, 
notably paraffin, were selectively attacked. 

A study of the fire hazard due to protective 
coatings on interior ship surfaces showed that 
the paint thickness should be kept at a mini¬ 
mum if the spread of fire from one bulkhead 
to another was to be prevented. Essentially 
complete protection was obtained by using not 
more than three coats of a paint containing not 
over 20 per cent binder, and by using anti¬ 
mony oxide as 10 to 20 per cent of the pigment. 
The Navy No. 84 primer was found to con¬ 
tribute to the flashing and burning; this was 
corrected by adding aluminum flake directly to 
the standard No. 84 primer before application. 


i6.2 INTRODUCTION 

Coating systems for ship bottoms should 
consist of two components: the anticorrosive 
paint, applied directly to the cleaned metal, and 
the antifouling topcoat. The purpose of the 
anticorrosive paint is to protect the metal from 
corrosion and to act as a base for the anti¬ 
fouling coat. It is necessary that it have good 
adhesion over long periods of exposure to both 




92 


ADHESION, BLISTERING, AND CORROSION 


93 


the metal and the topcoat. Regardless of its 
other properties, failure in adhesion will re¬ 
sult in fouling or corrosion or both. Other nec¬ 
essary properties are high moisture resistance, 
as measured both by permeability and by the 
softening or weakening of the film during 
prolonged contact with water; resistance to 
weak alkalies; the ability to form a tough film 
without excessive strains, shrinking, or expan¬ 
sion during drying; and the retention of its 
properties over the temperature range en¬ 
countered from the tropics to the subpolar 
regions. The purpose of the antifouling paint 
is to prevent the attachment or growth of 
fouling organisms. 

While the investigation of underwater coat¬ 
ings began with the emphasis on the antifoul¬ 
ing coat, it was soon apparent that the best 
antifouling paint was worthless unless it could 
be held on for a reasonable length of time. A 
satisfactory primer was therefore essential to 
a satisfactory antifouling paint. Further, the 
primer was greatly affected by the surface over 
which it was applied. Hence, a successful paint 
system is equally dependent upon surface prep¬ 
aration, primer, and antifouling paint. 

163 ADHESION, BLISTERING, AND 
CORROSION 

Mechanical Improvement of 
Adhesion 

Adhesion between the standard Navy primer 
and the hot plastic antifouling paint was not 
good and an attempt was made to correct this 
by mechanical methods, which would not ne¬ 
cessitate changes in the formulation of the 
paints. It was believed that increasing the 
available surface to both the primer and the 
plastic would improve the apparent adhesion, 
and granulated slate, sand, fiber glass, and 
aloxite were evaluated for this purpose. It was 
found that considerable improvement in adhe¬ 
sion and in the tendency of the plastic to sag 
at elevated temperatures was obtained by em¬ 
bedding sand in the partially hardened primer. 
This produced a surface similar to sandpaper 
with the granules protruding well above the 
surface. After the primer had dried thoroughly 


the hot plastic was applied with a hot spray 
gun. Impact tests of the standard system 
caused failure from lack of adhesion of the 
plastic to the primer. With the sand granules, 
more drastic treatment was necessary to cause 
failure, and the failure finally occurred from 
lack of adhesion of the primer to the metal. 

16.3.2 Primers and Corrosion 

Uncoated steel corrodes quickly in sea water, 
eventually yielding either the common red ox¬ 
ide (Fe 2 0 3 ) or the black oxide (Fe 3 0 4 ), both in 
the hydrated form. These same reactions may 
occur underneath a paint film. The formation 
of iron oxides is accompanied by a considerable 
expansion in volume and the development of a 
weak spongy deposit which pushes the paint 
film away from the metal and eventually de¬ 
stroys its continuity. 

These visible evidences of corrosion are ac¬ 
companied by chemical changes which also 
exert a destructive action on some types of 
paint films. Metallic iron in contact with 
aerated sea water first passes into solution as 
ferrous iron, forming ferrous chloride and 
sodium hydroxide. The ferrous chloride may 
change quickly to ferrous hydroxide and then 
more slowly to the black iron oxide (Fe 3 0 4 , 
4H 2 0), or the red iron oxide (Fe 2 0 3 , 3H 2 0), 
depending upon the amount of oxygen availa¬ 
ble. The alkalinity developed in contact with 
the underneath side of the paint film, due to 
the presence of sodium or magnesium hydrox¬ 
ides, is an important factor in the destruction 
of paint films in salt water. If the paint film 
is of a composition which may be saponified 
easily, it quickly softens and loses adhesion 
under this attack and permits corrosion to 
spread to adjacent areas. Thus, the use of vehi¬ 
cles having sufficient moisture and alkali resis¬ 
tance to withstand saponification is indicated. 
For instance, such materials as rosin or raw 
drying oils are easily saponified and have gen¬ 
erally yielded poor results in primer vehicles, 
while several types of synthetic resins and 
heat-polymerized drying oils have much greater 
resistance to saponification and have yielded 
excellent results. Other synthetic products such 
as chlorinated rubber, polyvinyl chloride, and 


ig QNEipENTTA T ^ 



94 


UNDERWATER COATINGS 


polystyrene also have excellent resistance to 
alkali and may prove useful in primers. 

Corrosion usually begins at isolated points 
where some defect in the paint film or in the 
cleanliness of the surface at the time of ap¬ 
plication permits the above reactions to start. 
It is almost impossible to avoid such defects 
entirely; the practical control of corrosion 
depends largely upon preventing it from 
spreading beneath the film from these localized 
spots, which is largely a property of adhesion. 

The chemical and physical factors that gov¬ 
ern adhesion, especially for underwater coat¬ 
ings, are so numerous and complex that the 
determination of satisfactory performance has 
had to depend almost entirely upon empirical 
tests. However, the requirements for ensuring 
adequate adhesion to metal may be stated 
briefly as follows: 

1. Ability to “wet” the metal surface com¬ 
pletely in order to obtain initial adhesion and 
avoid bare or thin spots during application. 

2 . Presence of “polar” groups to ensure a 
permanent bond after evaporation of any vola¬ 
tile constituents. 

3. High moisture resistance, as measured 
both by permeability and by the softening or 
weakening of the film in prolonged contact 
with water. 

4. High resistance to weak alkalies to avoid 
the saponification and softening action of alka¬ 
lies developed beneath the film. 

5. Ability to form tough, strong films with¬ 
out setting up excessive strains by shrinkage 
or expansion during or after the drying proc¬ 
ess. 

6 . A sufficiently wide range of temperature 
stability to ensure that the coating will not be¬ 
come too soft or weak at 90 to 100 F, or too 
brittle at 20 to 30 F. 

Unfortunately, no one bonding material now 
known possesses all these properties in a high 
degree; therefore it becomes necessary to for¬ 
mulate mixtures of the available materials to 
obtain the most suitable range of properties. 

The use of phosphoric acid in dilute aqueous 
or alcoholic solutions has long been established 
as one of the best known methods for pre¬ 
treating steel, zinc, and other metals to produce 
a passive surface and improve adhesion of sub¬ 


sequent coatings. For best results it has been 
necessary to use a hot dip process and careful 
control, which is impossible on ship hulls or 
other large structures. When phosphoric acid 
solutions are used cold, especially under vari¬ 
able field conditions, results are very erratic. 

It was found that mixtures of phosphoric 
acid and polyvinyl resins, applied to clean 
metal surfaces in dilute alcoholic solution, pro¬ 
duce exceptionally uniform, adhesive, and tough 
deposits to which subsequent paint coats 
tenaciously adhere. The superiority of this 
treatment over phosphoric acid alone, Deoxidine, 
and other proprietary products was most 
striking in the case of galvanized iron or sheet 
zinc, which have always been most difficult to 
paint satisfactorily. 

A film composed of 20 to 35 per cent phos¬ 
phoric acid and 80 to 65 per cent polyvinyl 
butyral resin pigmented with zinc tetroxy- 
chromate gave excellent adhesion to metal and 
freedom from blistering on soaking in salt or 
fresh water. A thin (0.5 to 1.0 mil) wash coat 
of this product alone did not give protection 
for an extended period of time, but did improve 
the performance of the paint system subse¬ 
quently applied. The outstanding property of 
the wash coat was its adherence to metal and 
its improvement of the adherence of the 
primer. Excellent adhesion was obtained on 
every metal to which it was applied, which in¬ 
cluded mild steel, stainless steel, unanodized or 
anodized aluminum, zinc or galvanized iron, 
copper, tin, and cadmium plate. Primers that 
had no adhesion to metals were used over the 
wash coat and the resulting system had ex¬ 
cellent adhesion. 

Blistering and peeling of paint films on ship 
bottoms have been rated the principal causes 
of failure in service, but there was very little 
information on the reason for this occurrence. 
In order to understand this more fully, several 
laboratory tests were set up to study the under¬ 
lying causes of paint failures. 

16.3.3 Mechanism of Blistering 

When steel is immersed in an electrolyte and 
made the cathode in an electrolytic circuit, 
hydrogen is liberated at the metal surface, 





ADHESION. BLISTERING, AND CORROSION 


95 


while the metal itself is protected from cor¬ 
rosion. This is demonstrated simply by immer¬ 
sing a bare steel panel connected with a strip 
of zinc in sea water for a few hours, when 
numerous small bubbles of hydrogen will be 
observed on the steel surface, and the steel will 
remain bright and uncorroded. If a permeable 
membrane, such as paint film, be introduced be¬ 
tween the steel cathode and zinc anode, the loss 
of hydrogen ions to form molecular hydrogen 
will tend to produce a corresponding increase 
in hydroxyl-ion concentration at or near the 
steel surface, thus increasing the under the 
paint film and setting up conditions favorable 
to osmosis. The paint film may thus be sub¬ 
jected to either hydrogen gas pressure or liquid 
pressure, or both, and blisters will form unless 
the adhesion of the film to the steel surface is 
sufficient to balance the opposing forces. 

This condition was caused in the laboratory 
by coating sandblasted steel panels on both 
sides, connecting them to strips of zinc and 
immersing them in sea water. Control panels 
similarly coated but not connected with zinc 
were also immersed and a third set was con¬ 
nected with copper strips. In every case where 
blistering developed it was much more rapid 
and severe on the zinc-coupled panels than on 
either of the other sets, though the steel be¬ 
neath the blisters was found to be bright and 
clean. The copper-coupled panels, as expected, 
showed very bad corrosion at isolated spots 
where there were any imperfections in the film 
and all the blisters were filled with rust. The 
Navy 84 primer showed numerous small 
blisters in 24 hours on the zinc-coupled panels, 
but required 10 days to blister visibly on un¬ 
coupled panels. Vinyl chloride-acetate copoly¬ 
mer resins, pigmented with zinc yellow, which 
yield films of high wet strength and rather 
poor adhesion, showed no blistering coupled 
or uncoupled in two weeks, but were found to 
have loosened from the steel on the zinc- 
coupled panels and to have permitted corrosion 
to spread beneath the film on the copper-coup¬ 
led and the uncoupled panels. Polyvinyl butyral 
resins, pigmented with zinc tetroxychromate, 
which yield films of good strength and adhe¬ 
sion but only fair resistance to moisture, 
showed no blistering or corrosion on any of 


the panels, except a few spots on the edge of 
the copper-coupled panels. These latter primers 
remained in excellent condition for three 
months, when the tests were discontinued, all 
other primers having failed badly in one form 
or another at the end of six weeks. 

An especially interesting observation on sev¬ 
eral of the uncoupled panels was the formation 
of two distinctly different types of blisters as 
little as Ys in. apart. One type had bright metal 
underneath and contained a liquid alkaline to 
litmus. The other type was badly rusted under¬ 
neath and contained a liquid acid to litmus. 
This illustrates the effects produced by local 
cells on surfaces, where the overall electrical 
potentials may be balanced, but still great 
activity exists at isolated small points. 

These effects have practical significance 
since it is known that potential differences 
varying from a few millivolts up to 2 to 3 v do 
exist on steel bottoms. Thus a large portion 
of the area may be cathodic, where blistering 
is apt to be accelerated, while the remainder 
of the hull is anodic, where corrosion is most 
severe. For this reason it appears that panel 
testing should be revised to include this factor, 
which can be done by connecting zinc strips to 
one set of panels and copper strips to another. 
By such means the ability of a coating to with¬ 
stand both cathodic and anodic conditions can 
be determined. 

In order to determine the permeability of 
various coatings to ions, a paper extraction 
thimble was coated on the outside with the 
material to be tested. The thimble was then 
placed in a test tube where it was surrounded 
by an agar gel containing a suitable indicator, 
and a solution containing the ion under con¬ 
sideration was placed inside the thimble. Pene¬ 
tration of the ion through the coating was indi¬ 
cated by a change in color in the agar gel 
adjacent to the coating. 

In one set of tests IV hydrochloric acid was 
used in the thimble with methyl red indicator 
in the gel; in another set sea water was used 
in the thimble and 5-p-acetamino-phenylazo-8- 
hydroxyquinoline in a slightly alkaline solution 
was used as an indicator for magnesium. In 
both instances polyvinyl butyral showed re¬ 
markable impermeability, with polystyrene 



96 


UNDERWATER COATINGS 


nearly as good. Phenolic films were not so 
good, and glyptal coatings failed very quickly. 

16 . 3.4 El ec t r j ca ] Resistance of Coating as 
a Measure of Deterioration 

Since it may be assumed that changes in the 
electrochemical equilibrium at the metal-paint 
interface are closely connected with the initia¬ 
tion of corrosion and blistering, and since such 
changes may be in progress long before their 
ultimate effects become visible at the outer 
surface of the paint film, it would be an advan¬ 
tage to be able to detect them immediately as 
they occur, thus making it easier to connect 
cause and effect. 

It has long been known that corrosion or 
solution of a metal is accompanied by a change 
in its surface potential, which can be measured 
accurately in relation to a standard, such as a 
calomel electrode. This appeared to be a re¬ 
liable and useful method of measuring the cor¬ 
rosion resistance of coatings in sea water, 
particularly since it had the advantage over 
most laboratory tests of approximating actual 
service conditions rather than being an “ac¬ 
celerated test” wherein abnormal destructive 
conditions prevail. 

A specially designed electrometer was con¬ 
structed which in principle was similar to the 
commonly used potentiometer systems. By the 
use of an electrometer tube as a null indicator 
in place of the usual galvanometer, coating 
resistance as high as 1,000 megohms could be 
determined with an accuracy of ±2 per cent. 
Since only a very small current flowed during 
the measurement, the coating was not subjected 
to any accelerated breakdown and the effects of 
polarization were negligible. For the purposes 
of avoiding contamination of the sea water 
and of eliminating junction potentials, a spe¬ 
cially constructed sea water-calomel reference 
half-cell was used. This half-cell was identical 
with the commonly used calomel references ex¬ 
cept that sea water instead of a potassium 
chloride solution was used as the aqueous 
medium. 

The cells as set up may be represented as 
mild steel-organic coating-sea water-calomel- 
mercury. The internal resistances of such cells 
may be determined by use of the electrometer. 


By subtracting the internal resistance obtained 
in a similar cell where the mild steel electrode 
is uncoated, the resistance due to the coating 
may be calculated. In the systems investigated, 
the internal resistance when the steel was bare 
was approximately 1,400 ohms, varying neg¬ 
ligibly with the extent of the corrosion of the 
steel. Since the internal resistance of cells in¬ 
volving coated steel varied between 1 megohm 
and 1,000 megohms when protection was good, 
this 1,400-ohm resistance had to be considered 
only when the coating approached failure. 

A thorough testing of coatings was not made 
with this equipment, but enough work was 
completed to demonstrate the reliability of this 
method of studying and evaluating organic 
coatings for protecting the hulls of seagoing 
vessels. Most of the results were obtained with 
clear coatings which cannot be used for pre¬ 
dicting the relative behavior of pigmented 
coatings containing the same vehicles. 

It was found that when the logarithm of the 
resistance in ohms of 1 sq cm of coating sur¬ 
face was greater than 8, it was accompanied 
by complete protection as long as the high 
resistance continued. A low or decreasing re¬ 
sistance (log R less than 6) was indicative of 
the onset of rust formation and film failure. 
With resistances between these two, the results 
were doubtful and depended on the trend of 
the change in the resistance. This method 
should be of considerable importance in fur¬ 
nishing information leading to the specification 
of better organic protective coatings for the 
hulls of seagoing vessels. By the proper control 
of variables, coating resistance studies should 
yield the quantitative effect on protectivity of 
such important factors as metal surface pre¬ 
treatment, drying time and aging, pigmenta¬ 
tion, inhibitive constituents, solvent, and thin¬ 
ner, as well as differences in the sea water en¬ 
countered in service. 

This method of study is apparently not lim¬ 
ited to steel substrates and a sea water envi¬ 
ronment. In general, coating resistance studies 
may be used with any metal substrate on ex¬ 
posure to all types of natural waters and spe¬ 
cial aqueous solutions. A limited number of 
tests with coatings on magnesium substrates 
exposed to sea water indicated that such a test 
may be valid with magnesium and magnesium 







ANTIFOULING COATINGS 


97 


alloys. This is important, since such substrates 
have been found to corrode seriously in prac¬ 
tice with little or no visible protective coating 
rupture. The results obtained to date show 
that although the protective coating appears 
to be in good condition its resistance is con¬ 
siderably lowered when the destruction of the 
magnesium is proceeding. 

From a more academic standpoint, resis¬ 
tance measurements may have some value in 
studying the rate of growth and distribution 
of corrosion products on certain uncoated metal 
surfaces immersed in aqueous media. Prelimi¬ 
nary results obtained in the study of uncoated 
magnesium partially immersed in sea water 
suggest that the resistance at the metal-liquid 
interface increases (0 to approximately 1,000 
ohms per sq cm) with the formation of the cor¬ 
rosion product. Further work is needed to sub¬ 
stantiate this possibility. 

In addition to studies on coated metal sur¬ 
faces continuously submerged in aqueous media, 
resistance measurements may be used in con¬ 
junction with intermittent immersion and with 
atmospheric protective coating tests. In the 
latter case conditions should allow for the oc¬ 
casional submersion in an aqueous medium re¬ 
quired for taking measurements. 

16 4 ANTIFOULING COATINGS 

1641 Introduction 

It is essential during war conditions to keep 
the bottoms of naval vessels free of fouling in 
order to avoid the consequent serious loss of 
speed, maneuverability, and fuel consumption. 
For example, the saving in fuel for ship propul¬ 
sion has been variously estimated at 20 to 50 
per cent in the case of a clean bottom as com¬ 
pared to a fouled bottom. Also the bottom coat¬ 
ings should have a long life and be easy to 
apply so as to reduce the frequency and time of 
docking to a minimum. 

At the beginning of World War II, the Navy 
coating practice consisted of brush or spray 
application of an anticorrosive primer, which 
required several hours to dry, followed by two 
coats of a varnish type of antifouling paint, 
containing rosin, coal tar, and toxic ingredients 
such as mercuric oxide and cuprous oxide. Ap¬ 
plication of these coatings was easy, but con¬ 


siderable time was lost in waiting for the vari¬ 
ous coats to dry. Partly on account of this, 
and partly because a thicker antifouling film 
than could be obtained by this cold application 
of solvent-containing paints was desirable, the 
antifouling coating was changed to a “hot 
plastic” containing no volatile solvents and ap¬ 
plied by means of electrically heated spray 
equipment at a temperature of 250 to 300 F. 
The hot plastic consisted of a mixture of 
paraffin, phenol-formaldehyde modified resin, 
mercuric oxide, cuprous oxide, and Paris green. 
This coating, designated as Mare Island plastic 
No. F-142, had excellent antifouling properties 
and had the further advantages of hardening 
very quickly on cooling, so that a ship could be 
returned to the water as soon as the coating 
job was completed, and of easily building up a 
heavy coating to a thickness of 50 to 60 mils. 

This coating had disadvantages, however, 
which served as a basis from which to start in 
the development of improved coatings. The 
necessary heating to 250 to 300 F involved 
rather troublesome equipment; it was difficult 
in cold weather to obtain a smooth homogene¬ 
ous film because of the rapid chilling of the hot 
compound when it touched the cold steel; rapid 
chilling caused excessive shrinkage and poor 
adhesion; in hot summer weather, the material 
was apt to remain too soft and produce exces¬ 
sive sagging. Thus temperatures above 100 F 
or below 50 F were outside the range of best 
conditions for application. 

The testing of hundreds of toxic materials 
for antifouling paints over the past century or 
longer has indicated that copper and mercury 
compounds are the most effective. These mate¬ 
rials are sufficiently effective to prevent fouling 
over periods of two years, and failure is gen¬ 
erally due to the vehicle rather than to the 
toxic. 

The vehicle must be of the proper composi¬ 
tion to permit the toxic to be at the surface in 
the correct amount. The use of a highly im¬ 
permeable vehicle may seal the surface so well 
that the poisons are prevented from diffusing 
to the surface, or the use of too permeable a 
vehicle may permit leaching of the poisons so 
rapidly that the supply is quickly exhausted. 
Thus, quantitative measurements of the rate of 
leaching should provide a reliable means of 



98 


UNDERWATER COATINGS 


determining the probable behavior of a paint 
and of studying the effects of variations in 
vehicle composition, pigmentation, poisons, and 
other important factors. 

164,2 Copper Leaching Tests 

At the beginning of this work it was ten¬ 
tatively assumed that the toxic copper or 
mercury compounds must be soluble in sea 
water and must be leached out of the support¬ 
ing matrix gradually enough and at just the 
right rate to maintain toxicity on the surface 
of the film or in the thin layer of slime that 
collects on all objects immersed in the sea. This 
was the theory generally advanced in most of 
the previous publications on the subject of 
fouling prevention. However, it was difficult to 
imagine a toxic layer consisting of an actual 
solution of copper salts that would not be 
washed away too rapidly, even by the slow 
movement of water in a quiet harbor, to permit 
an effective concentration of copper to be 
maintained continuously at or near the surface. 
Also, it seemed probable that if leaching should 
occur at a rate rapid enough to produce any 
appreciable concentration of soluble copper, the 
supply would soon be exhausted. If fouling 
prevention must depend upon soluble copper 
being continuously released from the paint film 
to the surrounding ocean, this apparently 
means that a paint composition must be devised 
which will be capable of releasing soluble cop¬ 
per at a rate neither too slow nor too fast, and 
that the rate must not vary greatly over long 
periods of time under service conditions where 
changes of temperature, speed of the ship 
through the water, and chemical composition 
of the water in different harbors, as well as 
progressive changes within the structure of the 
paint film, operate against the possibility of 
securing and maintaining any standardized or 
controlled rate of leaching. This seems an 
almost impossible assignment unless there are 
other factors not explained by the soluble 
poison theory. 

It was suggested that certain forms of cop¬ 
per or mercury compounds which are almost 
insoluble in sea water of pH 7.5 to 8.5, and 
which are now known to be formed at the paint 
surface by the chemical action of aerated sea 


water upon the more soluble metal compounds 
in the paint, may be the effective toxic agents. 
Evidence to support this theory was found in 
the fact that certain paints containing red 
cuprous oxide, finely divided metallic copper, 
cuprous chloride, or other soluble forms of 
copper, when immersed in aerated sea water, 
gradually formed a tightly adhering deposit of 
green or gray copper salts which were almost 
completely insoluble in sea water at a pH of 
about 8.0. 

This theory obviated the necessity for a con¬ 
tinuous leaching and washing away of soluble 
copper from within the film at a high rate in 
order to maintain a toxic concentration at or 
near the paint surface, but made necessary a 
chemical and physical structure in the paint 
film favoring the accumulation on its surface 
of insoluble copper salts in the form of a tight¬ 
ly adhering deposit or colloidal precipitate. 
Careful observation of those antifouling paints 
which yielded the most effective results on sur¬ 
face ships, including the Navy F-142 hot plastic 
and the Navy 15 R.C., disclosed that a green 
or gray deposit did form on the surface and 
that the time required for its formation varied 
greatly with the composition of the vehicles 
and the temperature. On a number of experi¬ 
mental paints exposed on panels at Miami, 
Guantanamo, and San Juan, good fouling pro¬ 
tection was invariably accompanied by a visible 
accumulation of green or gray-green copper 
salts on the paint surface. All other paints 
which retained their original red or brown 
color fouled badly. The exact composition of 
the copper salts was not determined, but it was 
believed they were a complex mixture of basic 
cupric salts, possibly containing some copper 
oxychloride and basic copper carbonate. 

To determine quantitatively the amount of 
copper leached out of a given paint composition 
and to study the factors controlling the for¬ 
mation of the green deposit, a simple labora¬ 
tory technique was devised. The paint under 
examination was applied to the outside surface 
of a glass test tube, % x 6 in., by dipping to 
a depth of 2 in. and was allowed to dry at 
room temperature in an inverted position. The 
average area coated was 80 sq cm. The coated 
tube was then suspended and centered by sup¬ 
ports in a larger test tube, 11 / 3 x 6 in., contain- 


^AFinENTIAg 



ANTIFOULING COATINGS 


99 


ing 50 cu cm of aerated sea water having a 
pH of 8.0. To accelerate th'e action, the tem¬ 
perature was maintained at 40 C by storing 
the samples in an oven with air circulation. 
At intervals of seven days, the water was re¬ 
moved along with any loosely adhering pre¬ 
cipitate. Fresh sea water was then added and 
the cycle repeated as long as any significant 
changes occurred. The water was analyzed for 
both soluble and insoluble copper by a colori¬ 
metric method employing sodium diethyldithio- 
carbamate in a 0.1 per cent aqueous solution as 
indicator. 

As the extraction cycle was repeated, it was 
noted that in the case of some paints, the 
original color of the paint gradually became 
masked by a chalky deposit which was firmly 
adherent. After varying periods of time, this 
deposit became thicker until it was visibly 
green or gray in color. With most types of 
finishes, the accumulation of a visible deposit 
coincided with a marked reduction in the quan¬ 
tity of copper released, leading to the belief 
that the insoluble deposit sealed the pores of 
the paint surface and so prevented further sub¬ 
stantial extraction of copper. Removal of the 
green salts by sanding or scraping usually 
caused a large increase in copper released 
during the next cycle. The green coating could 
also be quickly removed by immersion in dilute 
acid, and subsequent extraction cycles yielded 
results closely resembling the original values. 

A striking difference was noted, not only in 
the quantity of copper released, but also in the 
physical characteristics of the green precipi¬ 
tate from various paint compositions. In some 
cases a very fine-grained precipitate was 
formed which adhered tenaciously to the paint 
surface and could not be removed without 
drastic abrasion. In other cases, the precipitate 
did not adhere to the paint surface, but settled 
to the bottom of the tube, or could be removed 
easily by a stream of water or light rubbing. 
In some cases neither a green film nor an ap¬ 
preciable quantity of extracted copper was ob¬ 
tained. Some paints formed only a microscopic 
or iridescent surface layer while a few became 
green all the way through the paint. These wide 
differences were obviously connected directly 
with the composition of the paint vehicle, for 
the results with any given paint could be 


duplicated consistently or caused to change 
greatly by addition of other ingredients. 

Study of leaching rate curves for various 
types of copper-containing paints showed that 
a considerable period of time elapsed before a 
paint reached a condition of approximate 
equilibrium with its environment and came to 
a fairly constant leaching rate which could be 
maintained for a number of months. The time 
required to reach this equilibrium and then the 
further time that the constant leaching rate 
could be maintained were no doubt closely re¬ 
lated to both the physical and chemical struc¬ 
ture of the paint, but no reliable means were 
found to calculate or predict just how long 
any given paint composition should remain 
completely resistant to fouling. Comparison of 
leaching rates and results of actual exposure 
tests indicated that sustained leaching rates of 
8.2 mg of metal per 1,000 sq cm of surface per 
24 hours or above were usually accompanied by 
complete absence of fouling; the range between 
4.4 and 8.2 was somewhat doubtful; and leach¬ 
ing rates below 4.0 were accompanied by defi¬ 
nite fouling. However, the correlation between 
numerical leaching rates and actual fouling re¬ 
sistance was not conclusive. In several in¬ 
stances, very high leaching rates entirely failed 
to prevent fouling, while, on the other hand, 
several paints with very low leaching rates re¬ 
mained entirely free of fouling. Apparently 
the chemical composition at the paint surface 
was more significant than the numerical values 
for the quantitative amount of copper which 
escaped into the sea during any particular 
period. In other words, it appeared that bar¬ 
nacles may be less affected by copper actually 
in solution in the water surrounding a ship or 
test panel than by the almost insoluble precipi¬ 
tated copper salts which were formed, under 
favorable conditions, on the paint surface and 
in the pores of the paint near the surface to 
provide high surface concentrations of copper. 

16.4.3 Antifouling Coating Formulations 

Incorporation of rosin in antifouling com¬ 
positions greatly increased the amount of cop¬ 
per extracted during the first few weeks of im¬ 
mersion, probably by increasing the permea¬ 
bility of the vehicle to sea water and assisting 



100 


UNDERWATER COATINGS 


the diffusion of copper from the interior of the 
film. Also rosin tended to increase adherence 
of the insoluble salts to the surface, an effect 
that was considered to be very desirable. High 
proportions of rosin, however, tended to reduce 
the toughness of the film and made it more 
brittle, probably increasing its tendency to 
crack and erode. Therefore, while rosin was 
a valuable aid in making the copper within the 
paint film more readily available in an active 
toxic form, there was a limit to the amount 
that could be used without producing poor film 
properties and causing failure of the paint by 
cracking or erosion. 

The problem of producing a paint composi¬ 
tion capable of forming a toxic copper deposit 
on its surface must also take into account the 
ratio of copper to binder, and the amounts and 
types of inorganic fillers or pigments used. In 
general, a high ratio of copper tended to in¬ 
crease the amount of copper that could be ex¬ 
tracted by sea water, at least during the first 
few weeks of immersion, because the protec¬ 
tive layer of binder surrounding the copper 
particles was thinner. It might be expected 
that the highest practical ratio of copper would 
be most desirable, but the limiting factor was 
the toughness or bonding strength of the 
binder. Some of the more brittle, weaker types 
of binders, such as rosin, coal tar, or waxes, 
would not tolerate more than about two parts 
of total inorganic material to one part of 
binder without producing films that were too 
weak or friable to withstand the erosive action 
of the waves. On the other hand, the use as 
binders of the extremely tough, elastic types of 
products represented by the high molecular 
weight polymers of vinyl chloride, vinyl 
acetate, styrene, isobutylene, methyl or butyl 
methacrylates or other similar materials, per¬ 
mitted the incorporation of as much as four or 
five parts of inorganic material to one part of 
binder without producing an excessively weak 
or brittle paint film. 

Certain types of nontoxic inorganic fillers or 
extenders apparently had considerable value in 
these high pigment-binder ratios for several 
reasons. They replaced a considerable propor¬ 
tion of the expensive toxic copper or mercury 
salts and conserved the supply of these strate¬ 


gic metals. A more important consideration 
was their effect upon permeability of the film 
to sea water. The use of a pore-producing filler 
such as diatomaceous silica had the desirable 
effect of increasing the rate of diffusion of 
copper salts to the surface and also of im¬ 
proving the adhesion of the insoluble copper 
salts formed there in contact with sea water. 
Thus it became possible to use a highly water- 
impermeable type of binder, which resisted for 
long periods of time the softening and disin¬ 
tegrating action of sea water, and still re¬ 
tained a satisfactory rate of diffusion of toxic 
materials for maintaining an antifouling sur¬ 
face. 

Hundreds of panels were made with various 
anticorrosive and antifouling systems and ex¬ 
posed at Miami, Florida, and Mare Island, Cali¬ 
fornia, all of which appeared satisfactory in 
preliminary laboratory tests. Quite a few sys¬ 
tems remained perfect at the end of a year 
and several for eighteen months. Probably 
these finishes would have given protection for 
a longer period of time, but they were removed 
for examination of the film, the metal under 
the film, and for exhibition. 

The vehicles used in the exposure tests in¬ 
cluded a copolymer of vinyl acetate-chloride, 
polyvinyl butyral, polyvinyl acetate, chlori¬ 
nated rubber, polystyrene, chinawood oil phe¬ 
nolic resin varnish, dispersion resin, rosin, and 
zinc resinate. The pigments used were copper 
oxide, copper chloride, copper resinate, mer¬ 
curic oxide, and extenders. 

The oleoresinous binders have given good re¬ 
sults in primers and topcoats, but some advan¬ 
tages found in high-polymer binders made 
them appear more attractive. High polymers 
were tough and could be loaded highly with 
pigments without becoming brittle. Their dry¬ 
ing time was not appreciably affected by tem¬ 
perature since they depended only on solvent 
evaporation and not on oxidation or polymeri¬ 
zation for hardening. Their films underwent 
very little change on exposure to sea water, 
which was an important factor in that the con¬ 
dition of a film that was saturated with water 
was more important than its actual water 
transmission. A film that retained its tough, 
leather-like properties when saturated with 



ANTIFOULING COATINGS 


101 


water gave more permanent protection than 
one with high water impermeability but which 
became weak when saturated. Successive coats 
of polymers could be applied within a short 
time interval, even in freezing weather, as a 
small amount of residual solvent did not influ¬ 
ence the ultimate integrity of the film. In fact, 
those polymers that were alcohol-soluble hard¬ 
ened about the same in water as they did in 
air. 

Six panels remained in good condition after 
eighteen months of exposure. Formulas and 
exposure results of these six coatings are 
shown in Tables 1 and 2. These panels were for 
test of antifouling coatings only. A baked 


phenolic primer was used so as to avoid any 
primer failure. 

In the tests made, the best results were ob¬ 
tained using a binder of polyvinyl butyral or 
copolymer of vinyl acetate and chloride. There 
was not much difference in the behavior of the 
two resins for total submersion, but the butyral 
resin exhibited less cracking at tide level where 
the film dried out periodically. This choice of 
binding agent was applied to both anticorro¬ 
sive and antifouling paints, and by using the 
same type of binder for both coatings, better 
adhesion was obtained between coats. A com¬ 
plete coating system giving excellent results 
was: 


Table 1 . Exposure results of six tested antifouling coatings. 


Panel 

No. 

Composition* 

Exposure Per 

12 months 

iod and Performance Ratings 

18 months 

Relative 

overall 

rating 

Comments 

18 months’ exposure 

F.R.** 

C.R.f 

F.R. 

C.R. 

A.F. 

FilmJ 

A.C. 

Film§ 

2 

4.2 Vinylite VYHH 
12.5 Rosin 

83.3 Cu 2 0 

Sand granules in 2nd 
primer coat 

100 

100 

100 

100 

98 

100 

2 

Slightly rough owing to sand 
granules. Few small cracks 
in A. F. film. Remains 
sound after drying out. 
Adherent green surface 
deposit. 

3 

Same as panel 2 without 
sand granules 

100 

100 

100 

100 

98 

100 

1 

No defects except in edge 
trim. Remains sound after 
drying out. Adherent green 
surface deposit. 

13 

4.5 Vinylite VYHH 

4.5 Rosin 

45.5 Cu 2 0 

45.5 HgO 

100 

100 

100 

100 

98 

100 

1 

No defects except in edge 
trim. Cracks and peels 
after drying out. Adherent 
olive drab surface deposit. 

14 

8.3 Vinylite VYHH 

8.3 Rosin 

83.3- Cu 2 0 

100 

100 

98 

95 

95 

95 

3 

1 spot peeled f in. from edge. 
Cracks and peels badly 
after drying out. Adherent 
mottled green deposit. 

23 

57.3 Navy 15 R.C. 

5.1 Vinylite VYHH 

25.8 Cu 2 0 

11.8 Celite 

97 

Very 

few 

bar¬ 

nacles 

100 

90 

100 

90 

95 

4 

Peeling of A.F. coat at one 
corner. Few cracks after 
drying out, but does not 
peel. Adherent fawn color 
surface deposit. 

29 

59.4 Navy 15 R.C. 

5.2 Chlor. rubber 

21.1 Cu 2 0 

13.0 Celtite 

100 

100 

90 

85 

80 

80 

5 

Peeling and corrosion at all 
corners. Cracks and peels 
badly after drying out. 
Adherent fawn color sur¬ 
face deposit. 


* All these paints appeared physically sound on removal from test racks, but after drying out several days in the laboratory some 
cracked and peeled as noted above. 

** F.R. = Fouling resistance, 
t C.R. = Corrosion resistance. 

t A.F. Film = Physical condition of antifouling coat. 

§ A.C. Film = Physical condition of undercoats. 


























102 


UNDERWATER COATINGS 


Table 2. Important formulations. 



Per cent 
by weight 
paint 

Per cent 
by weight 
dry film 

WP-l Wash Primer 


Base A 



Vinylite XYHL resin (butyral) 

8.96 

38.2 

Zinc tetroxychromate 

8.54 

36.4 

Celite 165-S 

1.42 

6.1 

Monarch No. 71 black 

0.08 

0.3 

Butanol 

81.00 



100.00 

100.00 

Thinner 



Phosphoric acid (85 per cent 

15.2 

19.0 

H 3 P0 4 ) 



Ethanol-denatured 

84.8 



100.0 

100.0 

Mix in proportion of 77.2% Base “ 

A” and 22.8% Thinner 

within 24 hr of use. 



P-10 Primer 


Vinyl chloride-acetate resin VAGH 

17.0 

40 

Red lead 

25.5 

60 

Methyl ethyl ketone 

16.9 


Methvl isobutyl ketone 

20.3 


Xylol' 

20.3 



100.0 

100.0 

AF-14 Antifouling 

Paint 


Vinyl chloride-acetate resin VYHH 

5.9 

8.3 

Rosin 

5.9 

8.3 

Cuprous oxide 

59.4 

83.4 

Solvesso No. 1 

14.4 


Methyl isobutyl ketone 

14.4 



100.0 

100.0 


For wood-bottom ships good results were ob¬ 
tained by applying AF-14 directly to the wood. 
Another formulation (AF-22), containing 
metallic flake copper in place of cuprous oxide, 
was developed because of the short supply of 
the latter, and found considerable use on wood 
vessels of both Navy and Army. 

16 5 PAINT REMOVAL AND METAL 
CLEANING 

16.5.1 Chemical Paint Removers 

Improved paint removers were requested by 
the Navy for stripping of paint from aircraft. 


It was desired that the material be nontoxic 
and noninflammable, and since it was to be used 
largely on aluminum, it was necessary that it 
be inert to this metal. 

About 50 solvents were examined for strip¬ 
ping ability on the listed Navy paints. Lacquer 
L-12a: nitrocellulose base; Primer P-27B: zinc 
chromate, reduced congo, alkyd and phenolic 
resins; Enamel E-5: phthalic base; Enamel 
E-6: glyceryl phthalic base (baked); Varnish 
V-lOc: phenol-formaldehyde resin, tung oil; 
and Varnish V-llf: glyceryl phthalate base. 
The commonly used acetone-benzene mixture 
(50-50) was used for comparison. 

The most efficient paint strippers, without 
regard to other properties, were found to be 
(1) cyclohexylamine, (2) morpholine, (3) 
mesityl oxide, (4) methylene chloride, and (5) 
dichloroethylene. Of somewhat less effective¬ 
ness were ethylene dichloride, propylene dichlo¬ 
ride, trichloroethylene, 1,1,2-trichloroethane, 
and cyclohexanone. Of these materials cyclo¬ 
hexylamine and morpholine are harmful to the 
skin and irritating when inhaled, while cyclo¬ 
hexylamine appeared slightly corrosive to 
aluminum. Mesityl oxide has too low a flash 
point (33 F), is irritating to the skin, and is 
probably toxic. Ethylene dichloride and pro¬ 
pylene dichloride both have flash points of 21 F. 
Cyclohexanone is less active than most of the 
others as a paint stripper. The best material 
from all standpoints was methylene chloride. 

Various combinations of materials were 
tried, some of which were fairly satisfactory. 
The best composition was methylene chloride 
thickened with a small amount of cellulose ace¬ 
tate and rubber, previously dissolved in a mix¬ 
ture of 10 per cent ethanol in methylene 
chloride. 

Compositions very similar to this were ob¬ 
tainable commercially under the trade names 
Pyrox Remover (Pyrox Chemical Corporation, 
Long Island City, New York), Devoe-Raynolds 
Remover (Devoe and Raynolds Company, Inc., 
Philadelphia, Pa.), Saf-Te Remover (Wilson- 
Imperial Company, Newark, N. J.), I.C.D. No. 
9 (The Billings-Chapin Co., Long Island City, 
N. Y., The Glidden Co., Reading, Pa., and 
Telton, Sibley and Co., Philadelphia, Pa.). 








PAINT REMOVAL AND METAL CLEANING 


103 


Other high-flash formulations with satisfac¬ 
tory paint stripping properties were: 

1. Cyclohexanone (flash 

point 127 F) 80 per cent by volume 

Methylene chloride 10 
Carbon tetrachloride 5 
Tricholoroethylene 5 
Flash point of mix¬ 
ture 140 F 

2. Hexalin acetate 

(flash point 140 
F) 80 

Methylene chloride 20 
Flash point of mix¬ 
ture 150-155 F 


16 . 5.2 Mechanical Cleaning Methods 14 

Early in the work on the development of im¬ 
proved coatings for ship bottoms it became 
apparent that a common cause of paint failure 
was improper cleaning of the metal surface 
before application of the paint. In October 
1941, the three most important factors con¬ 
cerned with the improvement of coatings for 
the Navy were outlined in the order of impor¬ 
tance as (1) cleaning and preparation of metal 
surface, (2) anticorrosive and protective coat¬ 
ings, and (3) antifouling compositions. A 
recommendation was made to the Navy that 
sandblasting or steel shot-blasting be used for 
cleaning ship bottoms. Since dry sandblasting 
was objectionable because of the danger of 
abrasive damage of ship mechanisms, it was 
suggested that wet sandblasting be developed 
for this use. Up to this time the hulls had 
been cleaned by handscraping or by air- 
operated chisels, followed by wire brushing. 
This method did not obtain a surface in proper 
physical condition to secure best results from 
the anticorrosive primers applied. 

In 1942 an investigation of methods of clean¬ 
ing ship hulls was undertaken. Five possible 
cleaning methods were considered: chemical, 
electrolytic, flame, abrasive, and impact. 
Chemical cleaning was not considered satisfac¬ 
tory because of the character and size of the 
dock and ships. Investigation showed that it 
would be an expensive and time-consuming job 


and that the method of application and removal 
of the chemical might prove to be most trouble¬ 
some and injurious to dock structure and to 
the workmen. 

The best electrolytic methods for cleaning 
metals required submersion in a tank of acidic 
electrolyte solution. This would be impossible 
with a ship, and portable apparatus would be 
difficult to design. Sea water could perhaps be 
used as the electrolyte while the ship was in 
the fitting-out basin, but its use would be 
limited to that part of the operation. There was 
also doubt as to the penetrating ability of the 
electrolyte on the practically impervious layer 
of paraffin base antifouling paint on the hulls 
of most naval vessels. 

The flame method of cleaning hulls was not 
seriously considered because the Navy objects 
to the use of open flames in dry docks. It was 
doubtful whether flame would work well be¬ 
cause of the low melting point and inflammabil¬ 
ity of the plastic paint used. 

Abrasive methods such as revolving sand 
disks were fairly suitable for small boats and 
were in use by the Navy for this purpose. For 
large ships, however, the time allowed for re¬ 
coating was so sharply restricted that this 
method was considered too time consuming. 

Impact methods were believed to be the most 
promising field for investigation, and two sys¬ 
tems were examined: (1) impact from a 
mechanically operated member, and (2) im¬ 
pact from moving solid particle, such as sand 
or steel. 

Of the mechanically operated tools available, 
the best appeared to be a device manufactured 
by the Aurand Manufacturing and Equipment 
Company of Cincinnati, Ohio. This tool could 
be driven by either a pneumatic or electric 
motor, the former using a power source more 
available in Navy dry docks. The cleaning 
action was obtained by revolving a master 
wheel at high speed. About the periphery of 
the master wheel were groups of cutter wheels, 
shaped like milling cutters. The wheels were 
loosely fastened so that they flew outward 
under the action of centrifugal force. Thus the 
cutters, when permitted to make contact with a 
metal surface, flaked off such coatings of rust 
or paint as were present. 





104 


UNDERWATER COATINGS 


Laboratory tests with this tool on a variety 
of surfaces were promising enough so that 
practical tests were made on several cruiser 
hulls. One hull was badly pitted and corroded 
with a thick tough layer of black iron oxide, 
and over this surface was a heavy layer of 
Navy antifouling plastic. On this hull the 
Aurand tool was unsatisfactory because of the 
very slow rate of cleaning and because it failed 
to remove entirely the heavy oxide layer. These 
results were in contrast to those obtained on 
two other cruiser hulls which were in better 
condition. On the other cruiser hulls the 
Aurand tool produced a cleaner surface than 
was obtained with power chipping and at a 
somewhat faster rate. 

Tests with the Aurand tool were made on 
the superstructure and interior of one of the 
cruisers, and the tool appeared to be very satis¬ 
factory in rate and quality of work for remov¬ 
ing paint and cork insulation from light par¬ 
titions and bulkheads. It was believed that this 
type of cleaning instrument deserved further 
study and use for this type of work. 

For a study of wet sandblasting the Hydro- 
Blast system was investigated. This system, 
produced by the Hydro-Blast Corp. of Chicago, 
was used for cleaning foundry castings and in 
its commercial form was not portable. An 
examination of the unit showed, however, that 
it could be broken down into a relatively simple 
system that could be used in a dry dock for 
cleaning ship bottoms. The unit as modified for 
tests at the Brooklyn Navy Yard consisted of a 
high-pressure pump driven by a gasoline 
engine, which, together with a water reservoir, 
was mounted on a four-wheel chassis. A spe¬ 
cially designed portable sand hopper was used 
as a source of abrasive. Potassium dichromate 
was introduced in the water stream to inhibit 
the formation of rust on the cleaned steel 
plates. 

Tests showed that this equipment produced 
a very clean surface, but a number of me¬ 
chanical changes would have been necessary 
to make it satisfactory. 

Mare Island Navy Yard had been working 
on wet sandblast methods of cleaning ship bot¬ 
toms and developed a vapor sandblast which 
proved entirely satisfactory in producing an 


exceptionally clean surface at a rapid rate con¬ 
siderably in excess of power chipping. For this 
reason the NDRC investigation was discon¬ 
tinued. 

166 BACTERIAL EFFECTS ON METAL 
CORROSION AND PAINT 
DEGRADATION 21 24 25 

16,61 Introduction 

As a result of a study 1 of pipe line corrosion, 
it has been reported that of the factors respon¬ 
sible for corrosion, such as stray current elec¬ 
trolysis, acid, carbon contact, and differential 
aeration, anaerobic corrosion is second in im¬ 
portance only to stray current electrolysis. 
Anaerobic corrosion is the result of sulfate- 
reducing bacteria and is not self-stifling such 
as certain types of aerobic corrosion where the 
products exert an insulating effect. Under con¬ 
ditions favorable for anaerobic corrosion in 
soil, failure of steel pipes 0.2 in. thick has been 
noted in seven to eight years. 

It was determined that little information 
existed concerning the extent or severity of 
anaerobic corrosion of metals in the sea, al¬ 
though some scattered accounts suggested the 
possible destruction of metal by this type of 
corrosion. When these were considered with 
the information on corrosion in soil, it was 
concluded that the possibility of sulfate-reduc¬ 
ing bacteria being an important factor in the 
corrosion of ship hulls warranted investigation. 

Sulfate-reducing bacteria have the capacity 
of reducing sulfate to sulfide. During the devel¬ 
opment of these bacteria in soil, in sediments, 
and in water containing even small amounts 
of iron, the substrates turn black because of 
the formation of FeS. If there is an excess of 
sulfide over that combined with iron and with 
certain other cations, an odor of free hydrogen 
sulfide can be detected. One of the most char¬ 
acteristic features of locations where these 
bacteria develop is the presence of black iron 
sulfide, or the odor of hydrogen sulfide, or both. 
Reduction of sulfate is characteristic of this 
special group of bacteria; in fact, no organisms 
are known other than those belonging to this 
group which are capable of reducing sulfate to 


IWWII 



BACTERIAL EFFECTS ON METAL CORROSION 


105 


sulfide. These organisms are small curved rod¬ 
shaped bacteria, sometimes spiral-shaped. 
Their average size is 4X1 microns. They have 
been described under the generic names Spiril¬ 
lum, Microspira, Vibrio, Desulfovibrio, and 
Sporovibrio, all of which refer to the same 
group of organisms. A few species have been 
described, but these are all alike morphological¬ 
ly and differ only in the organic materials upon 
which they are able to grow. One of the most 
common species is the one named Sporovibrio 
Desulfuricans. 

These bacteria are particularly active in 
sediments of sea water and brackish waters; 
they are also widely distributed in terrestrial 
deposits. They can be recovered from agricul¬ 
tural soils as well as water-logged soils, but are 
active only under strongly reducing conditions. 
They are commonly encountered wherever cel¬ 
lulose and plant materials undergo decomposi¬ 
tion under anaerobic conditions. The sulfate- 
reducing bacteria do not develop on the cel¬ 
lulose directly, but on the products formed 
during the anaerobic decomposition of cellulose 
by other bacteria, including organic acids and 
alcohols. These bacteria are responsible for the 
large amounts of sulfide in the Black Sea (5 to 
10 ppm H 2 S at a depth of 350 to 1,150 fathoms) 
and for its black color, which is due to FeS. 
They are the principal source of the black iron 
commonly encountered in muds of tidal basins 
and marine sediments. 

The prevailing theory concerning the cor¬ 
rosion process was based on the work of von 
Wolzogen Ruhr, who established in 1934 the 
relationship of sulfate-reducing bacteria to 
this process. Experimental evidence was sub¬ 
mitted to substantiate the theoretical con¬ 
siderations. The following reactions are in¬ 
volved : 

8H 2 0 3=± 8H+ + 8(OH)\. . .. 

4Fe + 8H+ ^4Fe++ + 8H / Anodlcsolutlon of iron 
CaS0 4 + 8H -» H 2 S + 2H 2 0 + Ca(OH) 2 Depolarization 
Fe++ + H 2 S FeS + 2H+T„ . , . 

3Fe++ + 6(OH)+ -> 3Fe(OH) 2 / Corrosion products 

4Fe + CaS0 4 + 4H 2 0 -> FeS + 3Fe(OH) 2 + Ca(OH) 2 

Summary 

The bacteria are of principal importance in 
the corrosion process by reason of their ability 
to remove cathodic hydrogen. Whereas this is 


effected by dissolved oxygen under aerobic con¬ 
ditions, it is brought about under anaerobic 
conditions by the sulfate-reducing bacteria 
which simultaneously reduce sulfate. The sul¬ 
fide formed by this reduction reacts with part 
of the ferrous iron to produce ferrous sulfide. 
Ferrous hydrate is also produced and in larger 
amounts than ferrous sulfide; thus the cor¬ 
rosion products contain both ferrous sulfide 
and ferrous hydrate. Determinations made by 
von Wolzogen Ruhr on corrosion products 
showed a ratio of total iron to FeS, which was 
somewhat below the theoretical value of 4 to 1. 

166 2 Experimental Work 

In order to obtain an idea as to the distribu¬ 
tion of sulfate-reducing bacteria, samples of 
sea water were taken from Woods Hole and 
Buzzards Bay, Massachusetts; Brooklyn, New 
York; Barnegat Bay and Cape May, New 
Jersey; and Rure Beach, North Carolina; bot¬ 
tom sediments were taken from South Bristol, 
Maine; Woods Hole, Massachusetts; Cape May, 
New Jersey; Rure Beach, North Carolina; 
Miami and Biscayne Bay, Florida. All samples 
of both water and sediment gave positive test 
for the presence of sulfate-reducing bacteria. 

Painted and unpainted steel panels were sub¬ 
merged in sea water at Woods Hole, Brooklyn, 
Barnegat Bay, Stone Harbor (New Jersey), 
Rure Beach, and Miami Beach. At all sites the 
corrosion of the bare steel panels followed the 
same pattern; the amount of fouling varied 
with the location. Aerobic corrosion began im¬ 
mediately upon submersion with the formation 
of red ferric hydrate. In fouling areas, the 
fouling organisms attached themselves very 
soon. Fouling was not so severe on the bare 
panels as on those coated with an inert paint, be¬ 
cause the corrosion products tended to exfoliate 
and thus cause the fouling organism to break 
away. At the end of two to three months the 
corrosion products tended to adhere more 
tightly, and at about this time sulfide was first 
detected as a black material beneath the sur¬ 
face layer of red corrosion products. After 
four months a the entire surface of the panels 

a This time varied with the site. The longest period 
was about 7 months at Barnegat Bay. 




106 


UNDERWATER COATINGS 


was covered with the black sulfide-containing 
corrosion products with an overlying layer of 
ferric hydrate and, at most sites, fouling or¬ 
ganisms. The sulfide layer was sometimes soft 
and resembled graphite, but at other times 
occurred as a hard crust. This black material 
could be readily removed from the metal and 
revealed a bright silvery surface with no 
adherent protective material. Without excep¬ 
tion, the black corrosion products contained 
relatively large numbers of the sulfate-reducing 
bacteria. Upon exposure to the air the ferrous 
sulfide was rapidly oxidized to sulfate. A few 
ship bottoms were examined, and where the 
paint had failed the same type of corrosion 
was observed, red aerobic corrosion products 
acting as a barrier for the underlying black 
anaerobic corrosion products. The rate of cor¬ 
rosion of most of the bare steel panels de¬ 
creased during the exposure period where an¬ 
aerobic corrosion was assumed to be dominant, 
but was still fairly rapid. 

Since in all these exposure tests sulfate- 
reducing bacteria were found in abundance on 
corroding steel and a considerable amount of 
sulfide was found in the corrosion products, it 
was concluded that the bacteria were at least 
partly responsible for the metal destruction 
after the initial stage during which ferric 
hydrate alone is formed. The results failed, 
however, to establish an absolute relationship 
between development of sulfate-reducing bac¬ 
teria and corrosion of steel exposed in sea 
water, and a laboratory experiment was set up 
in the hope of obtaining more specific data. 
The results, however, were not satisfactory. 
For these tests, steel panels were degreased 
with solvent, sandblasted, and sterilized in sea 
water. They were then exposed in sterile, non- 
aerated sea water; sterile, aerated sea water; 
non-sterile, aerated sea water; aerated sea 
water treated with 0.05 per cent mercuric chlo¬ 
ride; and aerated sea water treated with 0.025 
per cent Santobrite (sodium pentachlorphe- 
nate). 

The results of this experiment did not dupli¬ 
cate results obtained in normal sea water 
exposure. The rate of corrosion was low in 
most cases and the corrosion products differed 
from those which prevail in the ocean. At no 


time was sulfide detected in the corrosion prod¬ 
ucts, and while sulfate-reducing bacteria were 
recovered in the non-sterile sample, they were 
in much smaller number than would be ex¬ 
pected if they were actively concerned with 
corrosion. The results are probably abnormal 
and do not reflect actual conditions. Some¬ 
what more satisfactory results might be ob¬ 
tained if the experiment were performed in a 
laboratory near the ocean where the panels 
could be exposed to a continuous stream of 
fresh sea water. 

Half of the painted panels which were ex¬ 
posed at the various sites were coated with an 
antifouling paint containing cuprous oxide 
over the primer, and the other half with a 
similar paint, except that it contained titanium 
dioxide pigment instead of the copper toxic, 
over the same primer. The inert paint quickly 
became fouled, and the slime and silt on these 
panels contained large numbers of sulfate-re¬ 
ducing bacteria, between 100,000 and 100,000,- 
000 per gram of material. This was the range 
of numbers characteristic of the black sulfide- 
containing corrosion products where the sulfate- 
reducing bacteria were presumed to be active 
in anaerobic corrosion. There can be no ques¬ 
tion but that the sulfate-reducing bacteria are 
widely distributed in the ocean by means of 
fouling organisms and suspended particles of 
organic matter. These organisms may in fact 
be the principal agency by which these bacteria 
are distributed. There was no indication, how¬ 
ever, that these bacteria affected the paint film, 
and where the paint was intact there was no 
corrosion of the underlying metal. Apparently 
the best preventive for anaerobic corrosion, as 
for aerobic corrosion, is an intact paint film. 

While some sulfate-reducing bacteria were 
recovered from the slimes on the antifouling 
coatings, the numbers were generally much 
smaller than occurred on the inert paint. It 
was also observed that if the slime from the 
antifouling paint was used to inoculate a 
medium for growth of the bacteria, growth did 
not occur when the highest amounts of inocu¬ 
lating material were used, but that growth did 
develop at higher dilutions. This indicated that 
the copper was toxic to the bacteria until suf¬ 
ficiently diluted. 



FIRE RETARDANT PAINTS FOR NAVY SHIPS 


107 


Slimes were examined which had formed on 
a number of copper-containing ferrous alloys 
after exposure at Kure Beach, North Carolina. 
The results indicated that sulfate-reducing bac¬ 
teria were present and apparently developed 
even in slimes which formed on copper-con¬ 
taining metals, even though some of these 
slimes contained considerable copper. In gen¬ 
eral, however, the slimes with the higher 
amounts of copper contained fewer of the bac¬ 
teria, suggesting that the copper exerted a 
toxic effect on the bacteria and tended to limit 
their development. 

Laboratory tests showed that ferric oxide, 
red lead, and lead chromate were comparatively 
nontoxic, whereas metallic copper, brass, solu¬ 
ble copper compounds, and zinc chromate were 
toxic to the bacteria. 

In order to obtain information regarding the 
relative rates of corrosion in strongly reducing 
sediments and in sea water, 12-ft steel rods and 
steel strips were exposed at Barnegat Bay and 
at Miami Beach. The specimens were driven 
into the bottom for a distance of 25 to 40 in. 
and most of the remainder was continuously 
submerged in the water. When examined at the 
end of six months, the portion which had been 
buried was bright with no adhering corrosion 
products, whereas the portion in the water was 
covered with red, crusted corrosion products. 
Measurements, however, showed that the loss 
of metal of the buried portion was as great as 
that of any portion of the specimen except for 
the section at the mud line, which was the most 
severely attacked. 

Further tests were made at Cape May, New 
Jersey, in which steel panels were completely 
buried in the mud and duplicate panels sus¬ 
pended in the water directly above. In these 
tests the loss of metal was considerably greater 
on the panel in the water than on the buried 
duplicate. 

16 6 3 Bacterial Attack on Paint 

The panel exposure tests which have been 
described indicated that anaerobic bacteria had 
no noticeable effect on the paint films used. 
Antifouling paint surfaces would only rarely 
be under anaerobic conditions, and since 


aerobic bacteria would be most apt to attack 
these materials, tests were made in the labora¬ 
tory to obtain some indication of the serious¬ 
ness of paint degradation by bacteria. For 
estimating the extent of bacterial development, 
determinations of bacterial numbers proved to 
have very little value, but significant differences 
were indicated by the rates of oxygen depletion 
of the sea water in which the specimens were 
exposed. Tests of Navy paints indicated that 
paints 14 R.C. and 143E were most rapidly 
attacked, 42A was nearly as susceptible, and 
15 R.C. and F84 the least affected. 

Of paint constituents tested, Vinylite VYHH 
(copolymer of vinyl chloride and vinyl acetate), 
Halowax, coal tar pitch, and chlorinated 
styrene appeared to resist bacterial attack com¬ 
pletely. Chlorinated rubber was slowly at¬ 
tacked, and with paraffin, alkyd, linseed oil, and 
two samples of phenolic resin the oxygen con¬ 
tent of the water was rapidly reduced. 

167 FIRE RETARDANT PAINTS FOR 
NAVY SHIPS 15 

A number of fires occurring on Navy ships 
at the start of World War II were aggravated 
by the burning of paint. This was particularly 
true of the paint on the bulkheads, which ac¬ 
celerated the spread of the fire from one burn¬ 
ing compartment to adjacent compartments. 
One of the reasons for the fire hazard was the 
large number of coats of paint which had been 
applied to some ships without cleaning off the 
old paint. This resulted in an extremely thick 
layer which contributed to any fire that started. 
Laboratory studies made both by the Philadel¬ 
phia Navy Yard and the NDRC showed that 
the thickness of the paint coating was the 
major contributing factor. This condition was 
quickly eliminated by removing all the old 
paint on interior surfaces and refinishing with 
not more than three coats of new paint. A 
further immediate improvement was made by 
reducing the amount of organic binder to about 
20 per cent of the dry paint film and by sub¬ 
stituting 10 to 20 per cent antimony oxide for 
other white pigments to produce a glazed or 
sintered residue at high combustion tempera¬ 
tures. 


^F W TIAI. 4 



108 


UNDERWATER COATINGS 


The apparatus used for testing the behavior 
of paints at high temperatures consisted of a 
welded steel box 13 in. wide by 13 in. deep by 
19 in. long, arranged so that the test could be 
run either with or without a cover on the box 
to exclude air currents. The paint systems to 
be tested were applied to steel panels and in¬ 
serted in the box in a vertical position approxi¬ 
mately 3 in. in front of the gas burner, the un¬ 
coated side being next to the burner. In most 
of the tests two 6 x 12-in. panels were placed 
side by side, each coated with a different paint 
for comparison, or a 12 x 12-in. panel could 
be used with two or more different paint sys¬ 
tems applied in strips. Each paint was tested 
with applications of one, two, or three coats, 
both with and without an anticorrosive primer 
coat. 

The gas burner was connected to a cylinder 
of gas such as butane, propane, or butylene, 
and compressed air and the mixture adjusted 
to give a hot blue flame. With this arrange¬ 
ment it was possible to heat the panel to red 
heat in about 20 sec. It was considered desira¬ 
ble to bring the panels to a high temperature 
very quickly to simulate more closely the effects 
of a shell or bomb burst. 

Observations during the heating period in¬ 
cluded the time and degree of flashing, the 
ability of the paint film to support combustion, 
and the tendency of the paint to blister and 
peel from the surface. A slight flash over the 
surface of a panel was not considered very bad, 
and in fact would probably be preferable to the 
gradual accumulation of sufficient unburned 
gases in a closed compartment to form an ex¬ 
plosive mixture. It was noted that, with all 
paints examined, the tendency to flash was in¬ 
creased considerably as the number of coats of 
paint increased. With many paints, a single 
coat of paint produced no flash, two coats a 
very slight flash, and three coats a definite 
flash. As long as drying oils, alkyd resins, or 
similar organic materials were used as binders 
for the paint, it was recommended that no more 
than three coats be allowed to accumulate. 

Paints which actually burn or support com¬ 
bustion after the gas burner is turned off were 
considered to be entirely unsatisfactory for 
use as interior coatings on ships. A number of 


experiments indicated that the proportion of 
pigment to combustible binder was a principal 
factor in the ability to support combustion. It 
appeared that a pigment content of at least 80 
per cent by weight of the dry film was desira¬ 
ble to prevent burning. A small amount of 
antimony oxide (10 to 20 per cent of the total 
pigment) was also found desirable, apparently 
due to the relatively low melting point of this 
pigment and its ability to flux and retard the 
free access of oxygen to the organic matter of 
the film. 

Paint systems which blister or peel during 
the high-temperature treatment were consid¬ 
ered undesirable, even when they did not flash 
or support combustion. Some paints, when 
heated very rapidly to 1000 C in 20 sec, popped 
away from the steel, throwing off glowing hot 
particles with considerable force. These hot 
particles, even though not actually aflame, 
could presumably ignite papers or other easily 
combustible material in a compartment some 
distance away from the hot bulkhead. 

During the testing it was noted that flashing, 
burning, and peeling were all accentuated when 
any of the new highly pigmented fire retardant 
paints were applied over the standard Navy 84 
primer, which has a relatively high proportion 
of oleoresinous vehicle and low proportion of 
inorganic material. This was rather disturbing 
because this primer was usually applied to all 
new steel for the Navy at the mill to prevent 
corrosion during shipment and construction, 
and was also used as the standard undercoat 
for repainting older ships. 

A means of overcoming this defect was 
found in the addition of aluminum flake to the 
Navy 84 primer before applying. With this 
addition, a marked reduction was noted in the 
tendency of the paint to peel, flash, or burn. 
This modification could be used without diffi¬ 
culty for repaint work after removal of all old 
paint, as the aluminum in powder or paste 
form could be stirred into the standard Navy 
84 primer very easily by painters on the job. 
Best results were obtained by mixing 1 pound 
of aluminum paste containing 80 per cent 
aluminum with 2 pounds of Navy 84 primer, 
though smaller amounts of aluminum gave 
noticeable improvement over the 84 primer 



FIRE RETARDANT PAINTS FOR NAVY SHIPS 


109 


alone. Other metals such as zinc powder were 
also tried in mixture with the 84 primer. Some 
improvement was noted, though results were in 
no case as good as those obtained with alumi¬ 
num. 

Several different types of paint formulations 
were tested in single- and multiple-coat ap¬ 
plications, both with and without the standard 
Navy 84 primer and its aluminum modification. 
These included the following materials: 

1. A linseed oil base paint corresponding to 
the Navy No. 29 inside white. 

2. The new alkyd resin base paint supplied 
by the paint laboratory at Philadelphia Navy 
Yard and covered by the Bureau of Ships Ad 
Interim Specification 52P22 (Int), November 
1, 1942. 

3. A water-emulsion paint based on a carbic 
anhydride-linseed composition as binder, with a 
high proportion of pigments: 


Carbic anhydride linseed resin 

15.31b 

Titanium dioxide 

42.4 

Antimony oxide 

10.2 

China clay 

32.1 


100.0 

This was thinned with water 
spraying consistency. 

to brushing or 

4. A proprietary water-emulsion paint widely 
used for interior wall finishing, Sherwin-Wil- 

liams Kem-Tone. 


5. A paint based on the flameproof Vinylite 
VYHH resin, a copolymer of vinyl chloride and 

vinyl acetate. 


Vinyl chloride-acetate copolymer 

resin 

VYHH 

15.31b 

Titanium dioxide 

42.4 

Antimony oxide 

10.2 

China clay 

32.1 


100.0 


This was thinned with ketones or ketone-hydro- 
carbon mixtures to spraying consistency. It 
was not suitable for brushing. 

The linseed oil interior paints previously 
used by the Navy, having a relatively low pig¬ 
ment content, flashed and burned very badly. 
Even two coats of the No. 29 paint were con¬ 
sidered somewhat hazardous, while three or 
more coats provided a definite fire hazard. 

The new 52P22 (Int) specification paint was 
definitely better in all fire retardant properties 
than the paints previously used. It did flash 


when two or more coats were applied and 
heated quickly to 1,000 C, but did not support 
combustion and did not blister or peel badly, 
except when applied over the No. 84 primer. 

The water-emulsion paint (3 above) ap¬ 
peared equal to the Navy 52P22 (Int) paint in 
fire retardant properties and had the added 
advantage that it offered no fire hazard during 
application or storage aboard ship, as it con¬ 
tained no volatile inflammable solvents. Its dis¬ 
advantages were that it could not be applied 
satisfactorily over rusty surfaces without the 
surface becoming stained by rust unless an 
oleoresinous or similar priming coat was first 
applied, and its resistance to scrubbing with 
strong soaps was not so good as was desired. 
It was also somewhat more difficult to spread 
evenly by brush application, though spray ap¬ 
plication yielded a very uniform and attractive 
surface appearance. Since fire prevention and 
control aboard ship is such an important 
matter, it would seem that further develop¬ 
ment work on the water-emulsion type of paint 
to overcome the defects noted while retaining 
the greater freedom from fire hazard, would be 
desirable. 

Examined proprietary water-emulsion paints 
were especially poor in fire retardant proper¬ 
ties, flashing and burning as readily as any of 
the oil base paints. This is probably due to the 
fact that they did not contain the high pig¬ 
mentation necessary for fire-retarding usage. 

Paints based on Vinylite VYHH resin, con¬ 
taining a high ratio of polyvinyl chloride, were 
the most resistant to flashing and burning of 
all the paints tested, providing they were 
thoroughly dry and free from solvents. Their 
resistance to peeling was not so good as several 
of the other paints, and there is the possibility 
that the acid fumes released at high tempera¬ 
tures might interfere with fire fighting by the 
ship’s crew. Because of their excellent resis¬ 
tance to moisture, alkalies, and acids, these 
resins meet other service requirements espe¬ 
cially well and because of their toughness, they 
may be loaded with an unusually high propor¬ 
tion of pigments without becoming brittle, thus 
reducing the amount of resin and objectionable 
fumes to a minimum. It is believed that they 
merit further consideration in any future work. 








Chapter 17 

CORROSION RESISTANT LININGS AND COATINGS 


171 SUMMARY 

S OME OF the most important though least 
spectacular service problems were those 
having to do with surface protection by the 
use of proper coatings. In addition to the 
problems of ship-bottom coatings (Chapter 16), 
several miscellaneous coating requirements 
were analyzed and coatings selected. 

One such problem was the need for a coating 
as a lining for chemical bombs and for shells to 
provide protection against mustard, lewisite, 
and certain smoke mixtures. The coating se¬ 
lected for this purpose was an unmodified heat- 
convertible phenol formaldehyde resin applied 
in a two-coat system to a total of 0.5 mil, and 
a CWS specification was prepared on the basis 
of the test data obtained. For coating the 
interior of bombs a method was developed 
which provided a uniform coat where spraying 
was impossible; the bomb was filled with coat¬ 
ing liquid and drained at a controlled rate 
through an orifice of proper size. 

An investigation of a number of possible 
linings for fuel and lubricant containers, espe¬ 
cially the 5-gallon “Blitz” can, led to the selec¬ 
tion of a phenol formaldehyde resin and the 
preparation of several QMG specifications 
covering their purchase. 

The coating and sealing of Navy projectile 
base fuzes and primers developed to be an 
especially important problem because of the 
number of duds caused by penetration of water 
and ammonia vapors into the primer. After 
laboratory and surveillance tests covering 
adhesion, moisture penetration, air leakage, 
and corrosion, three coatings were selected and 
recommended for the fuze body. A chlorinated 
synthetic rubber plasticized with tricresyl 
phosphate was found to be markedly superior 
to the shellac formerly used as a primer sealant. 

172 LININGS FOR CHEMICAL 

MUNITIONS 

Pure mustard gas (£ns-/?-chloroethyl sulfide) 
is fairly stable in contact with ferrous metals, 


and when made from thiodiglycol offers no par¬ 
ticular problem when stored in bare steel. Mus¬ 
tard made by the Levinstein process (H), 
however, is a mixture including some rather 
reactive components, and bursting of contain¬ 
ers from internal pressure has occurred after 
short storage in warm climates. (See Chapter 
10.) Decomposition of H is also accelerated by 
contact with steel, resulting in lowering of the 
vesicant content and deposition of a sludge 
which interferes with the ballistics of the shell 
or bomb. If methyl methacrylate thickener is 
used in the vesicant, the polymer is precipitated 
by the iron, causing wide variations in the 
viscosity of the filling. A coating was therefore 
desired which would protect the filling from 
deterioration resulting from contact with the 
container. From the standpoint of standard¬ 
ization and simplicity, it was desirable to use 
the same munitions for different chemical fill¬ 
ings. For this reason it was desirable that any 
coating used for H be satisfactory also for L 
(lewisite), WP (white phosphorus), FS (chlo- 
rosulfonic acid-sulfur trioxide smoke mixture), 
and FM (titanium tetrachloride). 

Twenty-eight types of potentially useful 
materials designed for coatings, seaming com¬ 
pounds, and crevice fillings were examined. 
The coating materials were applied to steel 
panels and tested for flexibility and adhesion 
at room temperature and at —40 C. For the 
resistance tests the coatings were applied by 
dipping or spraying on steel rods. The rods 
were placed in glass bottles and sufficient of the 
agent was placed in the bottle to cover half the 
specimen. The bottles were placed in an oil 
bath at 65 C and periodic examinations of the 
coating were made. Viscosity determinations 
were made on the agents after filtering. Suita¬ 
bility of the coating was judged largely on the 
basis of a 30-day test. Variations in the meth¬ 
od of application, film thickness, drying and 
baking conditions, and pigmentation were in¬ 
vestigated and their effect on both impact resis¬ 
tance and resistance to the agent was deter¬ 
mined. 


110 


LININGS FOR CHEMICAL MUNITIONS 


111 


The most satisfactory materials were the un¬ 
modified heat-convertible phenol formaldehyde 
resins. The stability of H in contact with steel 
coated with this material was as good as that 
in contact with glass. Sandblasting of the 
metal is preferable for adhesion but from the 
resistance standpoint is not essential. The 
coating should be applied as a two-coat system 
totaling approximately 0.5 mil. Adequate bak¬ 
ing is essential, particularly on those resins 
which cure slowly, and the importance of 
making the correct allowance for thermal lag 
in the heavier masses of metal cannot be over¬ 
emphasized. 

One air-drying coating (SDO, an acetylene 
polymer of du Pont manufacture) was found 
which had adequate resistance. In those places 
where baking facilities are not available or 
where baking is impractical for some other 
reason, a two-coat system of SDO can be used. 
It requires air drying for the equivalent of 
four days under well-ventilated, normal tem¬ 
perature conditions or forced drying at about 
140 F to an equivalent hardness. This finish 
should be applied over sandblasted steel at a 
total thickness of 0.5 mil. The second coat 
should be put on before the first is thoroughly 
dried to anchor it adequately. 

Pigmentation of both the SDO and phenolic 
coating materials is desirable but not essential. 
Its value is largely in controlling consistency 
and flow, in facilitating inspection, and, in some 
cases, in reducing cost. Titanium dioxide should 
be made the basis of this pigmentation and a 
dark tinting color added to the first coat to 
distinguish it from the topcoat and to show up 
incompletely covered areas. 

Favorable results were obtained in some 
laboratory tests with coatings and treatments 
based upon sodium silicate with or without the 
addition of corrosion-inhibiting salts. The re¬ 
sults were too inconsistent, however, to war¬ 
rant a recommendation of their use. Their 
cheapness and availability make them ex¬ 
tremely attractive. 

The two recommended coatings were resis¬ 
tant to H, L, and WP, fairly resistant to FM, 
but were not resistant to FS. Both FM and 
FS can be handled satisfactorily in steel if 
kept anhydrous. 


Among the water-soluble materials tested, 
polyvinyl alcohol was found to have good resis¬ 
tance to H and L. It would not be expected to 
perform well as a coating for use with WP 
filling because of the water present. This 
material should be of particular interest as a 
seaming compound, and if seam closures are 
found necessary on any vesicant-carrying 
munitions, polyvinyl alcohol plasticized with 
glycerol seems to offer the most promise. 

The following classes of coatings did not 
have adequate resistance to the vesicants: 

Oil-modified alkyds. 

Plasticized nitrocellulose. 

Plasticized urea-formaldehyde resins. 

Plasticized melamine-formaldehyde resins. 

Plasticized phenol-formaldehyde such as 
Bakelite XR-15376. 

Phenol-formaldehyde varnishes. 

Acid-condensed phenol-formaldehyde resin. 

P.F. resins from certain substituted phenols, 
such as Bakelite BL-8966. 

Conventional varnishes from soluble gums. 

Vinyl resins, with the exception of polyvinyl 
alcohol. Included were polyvinyl acetates. 

Phenol-urea-formaldehyde combination, such 
as Plaskon’s 389-4. 

Acryloids. 

Methacrylates. 

All hydrocarbon polymers except SDO. These 
include Buna S, perbunan, and butadiene dry¬ 
ing oil. 

Combinations of alkyds with many of the 
above. All combinations tested were unsatis¬ 
factory. 

Sulfur formaldehyde resin. 

Thiokol. 

Lactic acid resin. 

Plasticized polyvinyl butyral. 

Since most of the bombs for which linings 
were desired were constructed in such a way 
as to make spray application impossible, a new 
method of coating with a controlled film thick¬ 
ness was developed. This was a modification 
of the common industrial practice of dipping 
and withdrawing from the tank at a rate cor¬ 
responding to the normal flow of the coating 
down a free surface. This eliminates runs and 
sags and provides for uniform thickness from 
top to bottom. It was found that the bombs 




112 


CORROSION RESISTANT LININGS AND COATINGS 


could be satisfactorily coated by filling with the 
liquid and withdrawing it at a controlled rate 
through an orifice. By proper adjustment of 
per cent solids and orifice diameter, a uniform 
coating of any desired thickness can be applied. 
The rates of withdrawal and solids content to 
give a desired film thickness were established 
for a number of resistant coatings. Conditions 
for application to M47 and M67 bombs were 
worked out for a representative phenolic coat¬ 
ing and SDO. Resistance to corrosion is not 
affected by the method of application (spray, 
dip, or flow coat) as long as films of proper 
and uniform thickness can be secured. 

The recommendations resulting from this 
investigation were incorporated in specification 
CWS-196-131-207, which is a performance 
specification for phenolic coatings. 

17 3 LININGS FOR FUEL AND 

LUBRICANT CONTAINERS 

At the start of World War II no lining was 
applied to containers for gasoline and other 
petroleum products. This resulted in serious 
corrosion of the containers, and contamination 
of the liquid with rust, which plugged carbu¬ 
retors and fuel lines, seriously shortening the 
life of the container. This was especially true 
of the 5-gallon cans which were alternately 
filled and emptied, allowing contact of moist 
air with the surface between fillings. When 
linings were first used, a variety of types was 
applied. Some difficulty was encountered from 
peeling of the coating, which caused worse con¬ 
tamination than the rust, and some instances 
of increase in gum content of the stored gaso¬ 
line. There was no record of which types of 
linings were proving unsatisfactory, and an 
investigation was therefore undertaken to de¬ 
termine what material should be specified for 
this use. 

The coating properties required were good 
adhesion, flexibility, resistance to gasoline and 
moisture, and the ability to protect the coated 
metal from corrosion. The materials proving 
best on an overall basis were unmodified heat- 
convertible phenol formaldehyde resins even 
though they were not so flexible as might be 


desired. Although they do not have the general 
resistance characteristics of the phenolic coat¬ 
ings, several other products having better 
flexibility are equally resistant to gasoline. 
These include some products based on urea- 
formaldehyde and certain high molecular 
weight vinyl-type resins. Alkyds as a class are 
open to question, although certain of them 
might be satisfactory. 

The surface preparation of the metal was 
found to be as important as the type of coating 
used. Sandblasting, after removal of oil and 
grease, was found to be the most effective 
means of surface preparation, giving consider¬ 
able improvement in adhesion as shown by the 
definitely reduced tendency of the normally 
brittle phenolic film to flake off the surface. 

As the thickness of the coating was increased, 
the flexibility decreased. With sandblasted 
metal a thickness of 0.70 mil can be used with 
safety on small containers (up to 5 gallons). 
Substantially heavier coatings could be applied 
to 16-gauge and heavier metal used in the 
fabrication of large containers. If the metal is 
not sandblasted, thinner coatings should be 
used. 

A review of the conventional surface treat¬ 
ments indicated that they held no promise, and 
it appeared obvious that any effective solution 
would be found in only a coating, metal or 
organic, which would completely cover and 
protect the steel surface. Zinc-coated con¬ 
tainers were considered unsatisfactory due to 
deleterious effects which would result on ex¬ 
posure to water, especially sea water. While 
other metals were considered, this method of 
protection was not investigated fully, since 
organic linings were thought to be preferable 
from the standpoint of application and avail¬ 
ability. 

Flexibility of the coating was tested by an 
impact tester which produced, by sudden im¬ 
pact, a dent in the test panel with the convex 
button on the coated side about 1.5 cm in 
diameter and 4 mm in depth. Flexibility was 
measured by the degree, or the absence, of 
cracking at the apex of the extruded button. 
Adhesion was determined by the ease or diffi¬ 
culty with which the film could be removed 
from the button by superficial rubbing. 


iaXLMitTl \ T I AI 



SEALING OF NAVY PRIMERS AND FUZES 


113 


Resistance to corrosion was determined by 
exposure of coated test panels which had been 
subjected to the impact test to a mist of 20 
per cent sodium chloride solution. The measure 
of resistance was the number of days in the 
salt solution mist before failure of the film. 
Most products failed by loss of adhesion due to 
seepage of liquid under the film or by progres¬ 
sive corrosion from a weak point in the film. 
This test often showed up failure at the apex 
of the impact test button which was not obvi¬ 
ous before the test. 

The gasoline resistance and gum increase 
test consisted of immersion of small test panels 
coated on both sides in high octane aviation 
gasoline maintained alternately at 140 to 150 
F for 7 hours and at room temperature for 17 
hours for a total of 5 successive cycles, fol¬ 
lowed by a determination of the nonvolatile 
content. 

Typical clear organic coatings tested in¬ 
cluded straight heat-reactive phenol formal¬ 
dehyde resin, oil- and gum-modified phenolics, 
typical vinyl resins, heat-bodied drying oils, 
drying oil modified alkyds, alkyd-modified 
urea-formaldehyde resins, alkyd-modified mela¬ 
mine resins, nylon, several pyroxylin materials, 
shellac, polythene, a high molecular weight 
paraffin, methacrylate resin, and one or two 
other synthetic resins. Among coatings found 
to be acceptable from a gum increase stand¬ 
point were heat-convertible 100 per cent phenol 
formaldehyde resins, a 43 per cent dehydrated 
castor oil alkyd-modified urea-formaldehyde 
resin, a 43 per cent dehydrated castor oil alkyd- 
modified melamine resin, an experimental syn¬ 
thetic du Pont resin, and a high molecular 
weight vinyl resin. All others were either 
borderline cases or definitely poor. Of these 
coatings only the phenol formaldehyde resins 
were found to be outstanding in salt spray 
resistance, these coatings withstanding expo¬ 
sures of more than 45 days while the best of 
the remaining products did not last more than 
10 days. The phenolics, however, were very 
brittle, causing fine cracks to result in the im¬ 
pact test, and corrosion of the steel substrate 
was found to occur at the apex of the button 
after 2 or 3 days in the salt spray test. Despite 
this weakness, however, the phenolics were very 


resistant to underfilm corrosion, and failures 
were confined to the immediate vicinity of the 
break in the film. 

Pigmentation, although adding nothing to 
the essential resistance properties, was con¬ 
sidered desirable because it was found to im¬ 
prove adhesion slightly and to facilitate in¬ 
spection of coated containers. 

An evaluation was made of a coating (Cox, 
U.S. Patent 2,200,469) formed by the electro¬ 
lytic deposition on steel of mixed salts from sea 
water. This coating was not found to be satis¬ 
factory. The adhesion was poor, as shown by 
the impact test, and there was a tendency for 
the coating to powder off in gasoline. Several 
modifications of the coating method were tried 
in an attempt to improve the effectiveness of 
the coating, but none were as good as the 
patented process. 

On the basis of this investigation, the 
Quartermaster Corps issued specifications 
OQMG-165, OQMG-167, OQMG-168, and 

OQMG-183 covering the phenolic coating and 
its application to fuel and lubricant containers. 


17 4 SEALING OF NAVY PRIMERS AND 
FUZES 

1741 Introduction 

The investigation described was undertaken 
because of the failure of a proportion of cer¬ 
tain types of armor-piercing, shells to explode. 
Desensitization of the time fuze was found to 
occur after the fuzes had been assembled in 
the shells, caused by the action of water and 
ammonia vapors from the ammonium picrate 
explosive. Penetration of moisture to the mer¬ 
cury fulminate in the primer mixture took 
place along with severe corrosion of the metal 
parts in the explosive train. 


1742 Fuzes 

The principal laboratory tests employed in 
selecting the best coatings were tests of adhe¬ 
sion and of moisture permeability. Cadmium- 
plated steel, Duralumin, copper, and tin plate 



114 


CORROSION RESISTANT LININGS AND COATINGS 


surfaces were coated, force-dried for 1 hour 
at 150 F, and aged for one week before being 
tested for adhesion with a knife. As a second 
test of adhesion, two pieces of aluminum foil 
were coated, cemented together with a thermo¬ 
plastic adhesive at 120 C for 3 minutes, and 
then stripped apart in a Scott tensile tester. 
The force per inch width required to strip the 
foil was taken as the index of adhesion. 

For determination of permeability, the coat¬ 
ings were applied 1.0-mil dry thickness on non¬ 
moisture proof cellophane. These sheets were 
tested for permeability at 140 F with an atmos¬ 
phere saturated with vapors of a 1.0 per cent 
ammonia solution on one side and phosphorus 
pentoxide as a desiccant and ammonia absor¬ 
bent on the other side. Data obtained on un¬ 
coated cellophane provided a basis for cal¬ 
culating the permeability of the test coating. 

A wide variety of coatings was tested and 
compared with the Navy specification OS-1433 
(50-50 paraphenyl phenol-formaldehyde resin- 
chinawood oil as 52 per cent solution in xylol). 
The choice of plasticizers was limited to two — 
tricresyl phosphate (to improve flexibility and 
adhesion) and Aroclor 1254 (for minimum 
moisture permeability). The clear solutions 
were thinned to about 1.5 poises, which is a 
suitable viscosity for dipping or flowing. The 
consistency was further reduced for spraying. 
Titanium oxide, zinc oxide, and zinc yellow 
were tested as pigments (lead compounds can¬ 
not be used in the presence of ammonium 
picrate), with flake talc as extender. Zinc 
yellow was chosen as representative of cor¬ 
rosion inhibitors. The purpose of the pig¬ 
mentation was to reduce permeability, inhibit 
corrosion, improve adhesion, and reduce the 
tendency of the coating to penetrate into the 
detent springs of the fuze. In general the pig¬ 
ments did not greatly help corrosion or adhe¬ 
sion, and the zinc yellow tended to increase 
permeability. However, a pigmented form of 
OS-1433 was included in the recommendations 
because of the reduced tendency to penetrate 
into the detent springs. 

Coating tests on Mark 28 fuzes were carried 
out with a series of ten of the most promising 
unpigmented coatings, and with a second series 
of pigmented coatings. For the laboratory tests 


the fuzes were coated most successfully by dip¬ 
ping, and attempts to spray coat were general¬ 
ly unsuccessful. Film thickness was measured 
by a General Electric magnetic induction 
gauge. An air pressure of 40-cm water was 
applied to the inside of the sealed fuze to test 
for leaks. After coating by dipping for 2 
minutes the penetration into the detent springs 
was noted by testing the action of the springs 
when the nosepieces were revolved up to 3,000 
rpm. Of the ten unpigmented coatings, eight 
penetrated into the detent springs; all the 
vehicles could be made satisfactory in this test 
by pigmentation. 

Several hundred fuzes were tested in a 
humidity cabinet at 140 F in contact with 
vapors of 1 per cent ammonia solution in 
water. Pellets of weighed desiccant were placed 
in the sealed fuzes and removed for weighings 
at intervals of two weeks. Although the con¬ 
sistency of the data obtained in these tests is 
not good, various conclusions could be drawn. 
The OS-1433 (Bakelite XV-1657) with a nitro¬ 
cellulose sealer for the detent springs was 
better than many of the other unpigmented 
coatings tested. Vehicles showing equal or 
better promise were vinylite plasticized with 
either tricresyl phosphate or Aroclor 1254, 
Parlon-X (chlorinated synthetic rubber) 
plasticized with Aroclor 1254, and polyamide 
resin with Aroclor 5460. The Bakelite systems 
began to blister before two weeks. Vinylite 
and Parlon-X showed less corrosion and blister¬ 
ing, as did the polyamide resin. Butyl rubber 
and Saran coatings gave poorer results. Of the 
pigmented coatings the best was Bakelite XV- 
1657 pigmented with titanium oxide and talc, 
which showed no moisture penetration after 5 
weeks and which does not require a nitrocel¬ 
lulose sealer for the detent springs. Zinc yellow 
pigmentation generally showed poorer results 
than titanium oxide and zinc oxide. 

As a result of the laboratory and humidity 
cabinet tests three coatings were selected and 
recommended for surveillance tests on live am¬ 
munition. (1) Bakelite XV-1657 pigmented 
with titanium oxide, 27 per cent, and flake talc, 
73 per cent by weight; (2) Vinylite VMCH 
(vinyl chloride-vinyl acetate copolymer modified 
with maleic anhydride) plasticized with Aro- 





SEALING OF NAVY PRIMERS AND FUZES 


115 


clor 1254 (chlorinated diphenyl liquid), and 
(3) pigmented Parlon-X plasticized with 
Aroclor 1254, pigmented as in (1). 


17 ' 4 * 3 Primers 

The particular primer of concern was a 
delay element primer consisting of a copper 
primer cup, a layer of primer mixture on the 
bottom of the cup, and a tin sealing cup on 
top of the mixture. The space to be sealed was 
the annulus between the copper primer cup and 
the tin sealing cup. The sealant was dropped in 
after the two cups were assembled. The sealant 
previously used in production was shellac, 
which was used as the control in the tests. 

Some thirty sealing compounds were pre¬ 


pared and tested for ability to seal the primer 
against air leakage at 40-cm water and for 
moisture transmission in vapors of 1 per cent 
ammonia solution at 140 F. For the latter tests 
the explosive mixture was replaced with dry 
silica gel, and the desiccant samples were 
weighed at intervals of two weeks. In addition 
to these laboratory tests one thousand loaded 
primers were subjected to a surveillance test 
at Frankford Arsenal. After storage the 
primers were fired, using a type of sensitivity 
test in which the height of fall of a firing 
weight is reported. 

On the basis of the results obtained by the 
tests described, the sealant recommended was 
Parlon-X plasticized with tricresyl phosphate. 
This is considerably better than the shellac 
previously employed. 



Chapter 18 


CLEANING OF GASOLINE CONTAINERS FOR USE IN 
TRANSPORTING DRINKING WATER 


181 SUMMARY 

G asoline containers may be cleaned for 
use in transporting drinking water by 
filling with water and activated carbon and 
agitating for a few minutes. The mixture con¬ 
sists of 1 pound of activated carbon in 50 
gallons of water. 


182 CLEANING METHODS FOR 
CONTAINERS 

Since in emergencies it is often necessary to 
use gasoline containers for transportation and 
storage of drinking water, an investigation was 
made of methods of cleaning the gasoline con¬ 
tainers and of purifying the water, so as to 
avoid danger from the toxicity of the gasoline 
or lead contained in it. 

Several adsorbents were tested for their abil¬ 
ity to remove color, odor, and lead from water 
contaminated with gasoline. These materials, 
in the order of their effectiveness, were: acti¬ 
vated carbon, Amberlite IR-100, Zeo Karb, 
activated alumina, Amberlite IR-4, fuller’s 
earth, Supercell, and sand. 

The activated carbon could be used in the 
granular state in filter beds or added directly 
to the water in the powdered form and then 


filtered out by any available sand filter or 
strained out of small quantities of water by 
flannel cloth. For filter beds of 2-ft depth satis¬ 
factory results were obtained at a rate of filter¬ 
ing of 2.5 gallons per minute per sq ft area. 
If powdered carbon is added directly to the 
water, the amount required is 1 pound to 50 
gallons of water, and the container should be 
agitated for 10 to 15 minutes. 

The carbon treatment will rarely be neces¬ 
sary if the containers have been properly 
cleaned and if storage of water in the con¬ 
tainers does not exceed 40 hours. Five-gallon 
tins can be cleaned effectively by a thorough 
rinse with soap and water, followed by several 
rinses with clear water. Fifty-gallon drums 
can best be cleaned by steaming for 30 minutes 
and then thoroughly rinsing with water to 
which a small amount of powdered carbon has 
been added. Gasoline tank trucks should be 
steamed for at least 90 minutes and thoroughly 
flushed with water to remove loose scale. When 
removed, the water should be filtered through 
sand filters, and added protection may be pro¬ 
vided by the addition of 0.5 gram of powdered 
activated carbon for each gallon of water 
before the sand filtration. Gasoline tank cars 
should be cleaned in the same manner as the 
tank trucks except that the steaming should be 
for at least 6 hours. 


116 





Chapter 19 

PRODUCTION OF MAGNESIUM FLUORIDE 


SUMMARY 

M agnesium fluoride is used to coat optical 
lenses to reduce reflection from the glass 
surfaces. Although little of the material was 
required, it was specially prepared by a com¬ 
plicated technique, because spattering and out- 
gassing during the coating process caused the 
rejection of many lenses. In the investigation 
described it was found that a satisfactory ma¬ 
terial for the coating operation could be pre¬ 
pared by the simple process of melting impure 
commercial magnesium fluoride and holding it 
at 1475 C in a graphite crucible for 15 minutes. 


19.2 PREPARATION of fluoride for 
COATING LENSES 

Magnesium fluoride is used for coating mili¬ 
tary lenses, because it greatly decreases the 
light reflected from the glass surface and 
thereby increases the light transmitted. The 
coating operation is done in a bell jar under 
a very high vacuum, with the heated lenses 
held in the top of the jar. The magnesium fluo¬ 
ride, which is vaporized from a crucible in the 
bottom of the jar by a heated coil of tungsten 
wire close to the surface of the fluoride, con¬ 
denses on the surface of the lenses. The appar¬ 
ent color of the lenses changes through the 
spectrum and the coating operation is stopped 
when the desired color (pink) is reached. 

The standard Navy method of preparing 
magnesium fluoride was to heat chemically 
pure magnesium chloride with chemically pure 
hydrofluoric acid in a platinum crucible. Hydro¬ 
fluoric acid was added as many times as neces¬ 
sary to remove all the chloride. The fluoride, 
after drying, was heated for several hours at 
1050 C. This was a laborious and time-consum¬ 
ing operation which resulted in an expensive 
product. The material thus prepared occasion¬ 
ally sputtered and outgassed during the coat¬ 
ing operation, causing the formation of soft 


films on the lenses as well as defects wherever 
solid particles struck the glass. An imperfect 
coating required regrinding of the lens, so that 
one of the serious costs of the process was the 
spoiled lenses rather than the high cost of the 
magnesium fluoride. 

Experimental batches of magnesium fluoride 
were made from a variety of starting materials 
and given the standard heat treatment. While 
a fair product was obtained from most of the 
procedures, none of the products was definitely 
better than that made according to the Navy 
method. The various methods of preparation 
were: 

1. Magnesium metal treated with hydro¬ 
fluoric acid (resulted only in a slight reaction). 

2 . Magnesium metal treated with a mixture 
of nitric and hydrofluoric acids. 

3. Magnesium metal treated with formic 
acid. Resulting magnesium formate converted 
to fluoride with hydrofluoric acid. 

4. Magnesium metal treated with acetic acid. 
Resulting magnesium acetate converted to 
fluoride with hydrofluoric acid. 

5. Magnesium metal burned in air. Result¬ 
ing oxide and nitrite treated with hydrofluoric 
acid. (Burning of the metal was too vigorous 
for safety.) 

6. Chemically pure magnesium nitrate 
treated with chemically pure hydrofluoric acid. 

7. Magnesium fluosilicate decomposed to the 
fluoride by heating. (High cost and low yield.) 

8. Chemically pure light magnesium oxide 
and dense magnesium oxide, commercial mag¬ 
nesium oxide from mineral magnesite, sea 
water oxide (light and dense), U.S.P. oxide 
(light and dense), changed to fluoride with 
both technical and chemically pure hydrofluoric 
acid. 

Because of the similar, and unsatisfactory, 
results from all these samples, it was concluded 
that purity and method of production were not 
important factors, but that the heat treatment 
might be critical. It was suggested that if the 
fluoride were heated to fusion, most of the 


117 


118 


PRODUCTION OF MAGNESIUM FLUORIDE 


sputtering would be eliminated. The melting 
point of magnesium fluoride is 1395 C, which 
is higher than can be reached in an ordinary 
electrical or gas muffle furnace. An Ajax 3P2 
induction furnace was therefore used for heat¬ 
ing the fluoride to 1475 C. The melting required 
5 to 8 minutes; sputtering occurred until the 
sample was well melted. Sputtering and out- 
gassing of samples treated in this way were 
negligible during the coating operation. 

Crucibles made from Acheson graphite were 
used for the fusion. Magnesium fluoride, at 
high temperatures, has exceptionally strong 
slagging characteristics. Clay, porcelain, 
alundum, Norbide, and magnesium oxide cru¬ 
cibles were rapidly destroyed. Platinum is 
seriously injured by contact with many ma¬ 
terials at very high temperatures. The graphite 
at these temperatures oxidized, so that the 
more exposed top part of the crucible burned 
off and its capacity was gradually reduced 
until a new crucible had to be used. Some pro¬ 
tection was obtained by covering the crucible 
with an inverted Norbide crucible. 

Satisfactory samples of magnesium fluoride 
were obtained by fusion of material from every 
source. Since the purity did not appear to be 
important, commercial magnesium fluoride, 
selling for $17.00 per 100 pounds, was obtained 
from the Pennsylvania Salt Manufacturing Co. 
After this material had been held at a tempera¬ 
ture of 1475 C for 15 minutes, cooled and 
ground, it was tested by the Navy and reported 
as satisfactory. 

The analysis of this commercial fluoride was: 

Per Cent 


Loss at 100 C 3.2 

Loss on ignition 7.26 

Water soluble 7.49 

Silica None 


Per Cent 


Calcium None 

Magnesium 34.40 

Magnesium calculated as magnesium fluoride 88.06 

Fluorine 54.0 

Fluorine calculated as magnesium fluoride 88.55 


Iron, which is a common impurity in these 
commercial samples of magnesium fluoride, is 
gradually reduced to metallic iron which col¬ 
lects as pellets in the bottom of the crucible. 
The longer the mass is kept molten, the more 
completely is the iron reduced, as shown by the 
fuzed mass becoming more white and less yel¬ 
low in color. If the molten mass is allowed to 
cool and solidify in the crucible, a considerable 
portion of these pellets can be mechanically 
loosened and discarded. If the molten mass is 
poured from the crucible into a mold, these iron 
pellets become mixed with the magnesium 
fluoride and cannot be readily removed. There 
was no indication in any of the tests that the 
iron which was present in the final material 
caused any trouble. Molten magnesium fluoride 
contracts when it solidifies; hence, the solid 
magnesium fluoride can be easily removed from 
a crucible or mold. 

The time that the material was held molten 
varied from a few minutes to 50 minutes and 
there was no apparent correlation with the 
results obtained. Fifteen minutes appeared to 
be adequate. 

It was concluded that fusion of the mag¬ 
nesium fluoride before use was desirable re¬ 
gardless of the method of preparation, and that 
satisfactory material could be prepared by the 
simple fusion of commercial magnesium fluo¬ 
ride, thereby avoiding the troublesome stand¬ 
ard method of preparation. 



Chapter 20 

SUBSTITUTE FOR CORK IN ORDNANCE PLUGS 


20.1 SUMMARY 

S atisfactory ordnance plugs for shell cas¬ 
ings can be made from waste wool shear¬ 
ings and a thermosetting phenolic resin, the 
molded product being coated with a beeswax- 
turpentine-graphite coating. 

202 PLUGS FROM WOOL WASTE 

Because of the shortage of cork the Navy 
Bureau of Ordnance desired the development 
of a substitute material which could be used for 
making plugs for shell casings. This material 
was to be made from noncritical materials; 
have approximately the same resilience, com¬ 
pressive strength, and aging characteristics as 
cork; afford similar protection against mois¬ 
ture; disintegrate upon firing; and be in line 
with cork in cost. 

Materials considered were cellulosic agricul¬ 
tural wastes, paper pulp, leather scrap, animal 
hair, textile wastes, and reworked rags or 
shoddy, using binders such as pitch or asphalt, 
adhesives in water or other solvents, thermo¬ 


plastic resins or thermosetting resins. The best 
of these proved to be wool shearings bound 
with about 20 per cent thermosetting phenolic 
resin. A waterproof coating of rubber latex 
or shellac was used, on top of which was 
painted the standard beeswax-turpentine- 
graphite coating specified for cork plugs. 

The manufacture involves the following main 
steps. 

1. Disintegrating and blending of the incom¬ 
ing wool stock. 

2. Mixing molding powder and wool. 

3. Weighing out and filling molds. 

4. Molding or curing under heat. 

5. Waterproof and beeswax coating. 

The curing time in the mold was about 30 
minutes at a temperature corresponding to a 
steam pressure of 110 pounds. Plugs for tests 
were made in a three-piece steel mold dimen¬ 
sioned to compensate for shrinkage. The mold 
was placed between the steam-heated platens 
of a hydraulic press with top and bottom sur¬ 
faces in contact with the platens in order to 
transmit the heat necessary for curing. Plugs 
made in this manner satisfactorily fulfill the 
requirements. 




119 


Chapter 21 

IMPROVEMENT OF SUBMARINE STORAGE BATTERIES 


21.1 SUMMARY 

A n exploratory study indicated that the 
- capacity of submarine storage batteries 
may be increased appreciably by employing 
stronger acid with appropriate modifications 
of the plate thicknesses and spacing. 

212 USE OF STRONGER ACID 

The ability of a submarine to remain under¬ 
water is limited by the capacity of its storage 
batteries. When these are discharged, it is 
necessary for the submarine to surface and 
recharge the batteries with the diesel engines. 
Since the batteries are exceedingly heavy, the 
number of them cannot be increased. If the 
capacity could be increased, the time under 
water could be increased or the weight carried 
could be reduced. Because of this situation, an 
exploratory study was made of possible meth¬ 
ods of increasing the capacity of lead storage 
batteries. 

The chemical reactions occurring in this type 
of battery are: 

1. At the negative plate 

2( + ) + Pb + H 2 S0 4 = PbS0 4 + 2H + 

2. At the positive plate 
Pb0 2 + H 2 S0 4 +2H + -> PbS0 4 + 2H 2 0 + 2 (+) 
From these equations, it is apparent that in 
the standard battery there is an excess of lead 
and lead oxide over that which will react with 
the acid. Theoretically, an increase in the con¬ 
centration of the acid from the standard 
density of 1.28 to 1.40 would increase the ca¬ 
pacity per unit volume by 45 per cent. Actu¬ 
ally, however, the effect of strong acid is to 
decrease the capacity of the negative plate. 
This decrease in capacity occurs during dis¬ 
charge and is probably due to coating over a 
portion of the active lead of the negative plate 
with lead sulfate. The lead sulfate is less 


soluble in strong acid, and the strong acid is 
more viscous and so decreases the rate of diffu¬ 
sion. The positive plate is not injured by acid 
densities up to 1.50. 

In the standard batteries the ratio of posi¬ 
tive to negative plate thickness is 0.081 to 
0.071 in. This ratio gives about equal utiliza¬ 
tion of positive and negative material using 
1.28-density acid. When stronger acid is used, 
however, this ratio is not correct because the 
positive plate becomes relatively more efficient, 
and a decrease in the capacity of the battery 
results. However, if the plate thicknesses are 
adjusted to the proper ratio for the concentra¬ 
tion of the acid used, a gain in the capacity of 
the battery can be obtained. The plates must be 
thickened and the acid space made less if full 
advantage is to be taken of use of stronger acid. 

It was considered unwise to use acid stronger 
than 1.37 because the gain in capacity above 
that point involves use of exceedingly heavy 
batteries. Calculations based on experimental 
results indicated that by proper design it is 
possible to gain about 35 per cent increase in 
capacity for the same size battery by increas¬ 
ing the acid strength to 1.37, and changing the 
size of the plates and acid space. Such a bat¬ 
tery would have negative plate thickness of 
0.102 in., positive plate thickness of 0.101 in., 
and acid space of 0.045 in., as compared with 
the standard negative plate thickness of 0.071, 
positive plate thickness of 0.081, and acid space 
of 0.070. These calculations were checked 
roughly 1 by partially filling the acid space of 
standard cells with sand, and testing with the 
stronger acid. This battery showed an increase 
of capacity of 25 per cent. These experiments 
were carried no further, and should be checked, 
but they indicate that by suitable modification 
of plate thickness, spacing, and acid density, it 
may be possible to increase the capacity of sub¬ 
marine batteries by as much as 35 per cent. 




120 


Chapter 22 

REMOVAL OF OIL FROM HARBOR WATERS 


22.1 SUMMARY 

O IL spills may be removed from harbors by 
spreading “doped” sand on the water and 
carrying the oil to the bottom with the sand. 
The most effective dope was a mixture of higher 
aliphatic amines. The amount of dope and sand 
required is so large that the method is practical 
only in special situations. 

Information on industrial techniques of han¬ 
dling oil spills was collected and reported. 

22.2 USE OF TREATED SAND 

Oil spills on harbor waters are apt to occur 
as a result of enemy action against ships and 
shore storage tanks. These spills are a hazard 
because of their inflammability, and the heavier 
oils are a serious nuisance to salvage opera¬ 
tions. When the oil is in large patches on fairly 
unconfined water, the easiest and most economi¬ 
cal method of collecting it is by skimming with 
suitable equipment. The available information 
on this method of removal was compiled. 1 

An investigation was made of the use of 
chemically doped sand for sinking the oil. Tests 
showed that thoroughly dried sand carries down 
the oil but does not hold it down. If the sand 
was treated with one of several effective chemi¬ 
cals, the amount of oil carried down was not in¬ 
creased but the oil was held on the bottom. The 
sand was treated simply by soaking in a solu¬ 
tion of the chemical for a few minutes and 
draining. It was not necessary to dry it. The 
materials found effective for the treatment of 
the sand were Armour amine acetate, Armour- 
free amine, Shell paramine hydrochloride, and 
Tretolite Reagent L-28,097. All these are high 
molecular weight amines or the esters. Of these 


the Armour amine acetate had the optimum oil¬ 
sinking performance. This is the mixed acetates 
of 25 per cent mono-w-octadecyl amine (CH 3 
(CH 2 ) 16 CH 2 NH 2 ), 25 per cent mono-n-hexa- 
decyl amine (CH 3 (CH 2 ) 14 CH 2 NH 2 ), and 50 per 
cent mono-w-octadecenyl amine (CH 3 (CH 2 ) 7 
CH :CH (CH 2 ) 7 CH 2 NH 2 ). 

The ratio of the weight of oil carried down to 
weight of sand increased as the sand size de¬ 
creased, but the amount of dope required also 
increased. Silica sands from many sources ap¬ 
peared to have comparable oil-sinking perform¬ 
ance. Crushed limestone required more dope 
than the corresponding size of silica sand and 
was not so effective. The weight of sand and 
Armour amine acetate dope required per 1,000 
barrels of oil for film reduction from 0.20 to 
0.05 in. is given in the following table. 

Silica Sand Size (Inches) 

0.0013 0.003 0.005 



Sand 

(tons) 

Dope 

(lb) 

Sand 

Dope 

Sand 

Dope 

Gasoline 

263 

10,230 

317 

5,390 

395 

4,100 

Diesel fuel 

465 

18,100 

512 

8,810 

574 

5,970 

Bunker “C” 

530 

20,700 

585 

10,050 

656 

6,820 


The sand-doping and oil-sinking processes 
were carried out in sea or fresh water with 
equal effectiveness. 

A basic characteristic of the chemical-sand 
method is the fact that the oil cannot be re¬ 
claimed at reasonable cost after adsorption by 
the doped sand. This loss, in addition to the cost 
of the chemical (about 30 cents per pound), 
makes this procedure less economical than me¬ 
chanical removal, but it may be more advan¬ 
tageous in special situations such as burning 
films, restricted areas such as dry docks, appli¬ 
cation by air guns already available, and so 
forth. 




^MlllWiraTT If 


121 




Chapter 23 

PRODUCTION OF NITRIC ACID FROM URINE 


23i SUMMARY 

P roduction of nitrates from urine is prac¬ 
tical as an emergency measure in thickly 
populated countries. A solution of approxi¬ 
mately 1 per cent ammonia may be obtained by 
the action of common bacteria on human urine, 
or by the use of the enzyme urease obtained 
by water extraction of soybean meal. One ton 
of ammonia is obtainable each day from the 
urine of about 85,000 people. The ammonia so 
obtained must be concentrated and oxidized to 
nitric acid in standard equipment. 

Alternatively, the urine may be nitrified by 
natural bacteria in aerated beds of broken lime¬ 
stone or other material, producing from 1 cu m 
of bed about 30 grams of nitrate nitrogen per 
day as a solution containing 1.75 per cent cal¬ 
cium nitrate. This method obviates the special 
chemical plant equipment for ammonia oxida¬ 
tion. 

23.2 INTRODUCTION 

The loss of the Burma Road in 1942 cut off 
practically all supplies to China, so that every 
effort was made by the Chinese to increase 
their limited production facilities. One of their 
greatest needs was for propellent explosives 
for small arms ammunition. This use required 
nitrocellulose, but they had no adequate nitric 
acid production and their stock pile of nitrates 
(Chile saltpeter) was practically exhausted. 
One large source of nitrogen was human urine, 
and an investigation was made to determine the 
best way of utilizing this. The use of urine was 
deemed feasible because collection systems were 
in operation in most Chinese cities. No sew¬ 
age systems were used and the urine was col¬ 
lected and spread on the farm lands as fer¬ 
tilizer. One ton of ammonia can be produced 
from about 35,000 gallons of urine, which is 
approximately the amount per day from 85,000 
people. One ton of ammonia is sufficient to 
produce over 3 tons of 100 per cent nitric acid. 


The nitrogen in human urine can be easily 
converted to ammonia by either bacterial or 
enzyme action. The product contains 0.8 to 
1.0 per cent ammonia and must be concen¬ 
trated by simple distillation to obtain a product 
suitable as feed to an ammonia oxidation plant 
for producing nitric acid. The Chinese con¬ 
tracted directly with a United States company 
for the design of an oxidation plant so that 
this part of the process was not investigated 
by NDRC. It is also possible to convert the 
nitrogen to nitrates completely by bacterial ac¬ 
tion. The results indicated that these processes 
were operable and that they might be practical 
where it was impossible to obtain equipment 
for a more modern process, and particularly 
where a collection system was already in opera¬ 
tion. The choice of the process used would de¬ 
pend upon local conditions and supplies. 

23.3 AMMONIFICATION 1 

A wide variety of bacteria, actinomyces, and 
fungi split urea to form ammonia and carbon 
dioxide. These occur in soils, fresh and salt 
waters, muds, sewage, and the feces of man and 
animals. They abound in manured soils. Vig¬ 
orous ammonifiers appear in practically all gen¬ 
era of saprophytic bacteria, cocci, and bacilli. 
The process goes on under both aerobic and 
anaerobic conditions and over broad ranges of 
temperature and hydrogen-ion concentration. 

Normally voided urine, collected without 
sterile precautions and stored without adding 
bacteriostatic preservatives, will be naturally 
inoculated with a mixed culture of urea-split¬ 
ting organisms and others capable of hydro¬ 
lyzing uric and hippuric acids almost quanti¬ 
tatively to ammonia. The practical problems in 
large-scale processes are (1) bringing about 
ammonification in a convenient interval, and 
(2) preventing loss of volatile ammonia. 

Conversion of the urea to ammonia can be 
accomplished by simply letting it stand, but 
this may require as long as a week. If inocu- 


122 


AMMONIFICATION 


123 


lated with 10 per cent of fermented urine from 
a previous batch, the reaction will be com¬ 
pleted in about 24 hours. Because of the ease 
of this reaction, ammonia will be formed be¬ 
fore and during collections, and precautions 
should be taken to prevent loss of this am¬ 
monia. Such precautions are frequent collec¬ 
tions (each day preferably) and the use of 
covered containers, or containers having a 
minimum surface exposed to the air. 

A series of tanks should be provided for fer¬ 
mentation. The size of the tanks is not impor¬ 
tant and may be governed by the ease of fabri¬ 
cation and the necessity of heating them. They 
may be made of any material capable of resist¬ 
ing 1 per cent ammonia at pH 9.0. Either iron 
or ceramic is satisfactory, the iron, of course, 
being the easier to heat. Since the loss of am¬ 
monia occurs at the air-liquid interface, this 
area should be kept as small as possible by 
using covered deep tanks. Some means of heat¬ 
ing the tanks slightly must be provided. Direct 
firing should be satisfactory, or pre-heated 
urine may be run into wood vats or tanks kept 
in a warm room. 

Human urine, the urine of domestic animals, 
and the feces of domestic fowls may be used. 
Pollution with animal or human feces, rubbish, 
paper, etc., however, will actually cause a lower 
yield by binding part of the ammonia nitrogen. 
The material is placed in the tanks with 10 
per cent of the material left from the previous 
batch and heated, if necessary, to bring the 
temperature to 25 to 30 C. At 20 C, or below 
the rate of ammonification, the process is not 
only slower, but is also unpredictable and varies 
more from one batch to another than at the 
higher temperature. The first batch may be 
started by seeding with old urine, manure, or 
soil. When the ammonification is complete, 90 
per cent of the fermented urine should be 
drawn off and replaced with new urine. The 
remaining 10 per cent of each batch should be 
an adequate starter for the new charge. For a 
batch seeded with 10 per cent of fermented 
urine, the hydrolysis to ammonia should be 
complete in about 24 hours. 

There will be no effervescence during the fer¬ 
mentation unless gross organic pollution of the 
urine occurs, and only the volume changes due 


to temperature variation of the liquid need to 
be considered when estimating the space to be 
left at the top of the tank. 

The completion of the hydrolysis may be de¬ 
termined approximately by titrating with 
standard acid using methyl red as indicator. 
When no further increase in the titration is 
observed, the hydrolysis is essentially complete. 

The effect of dilution on the reaction was 
investigated and it was found that a 50 per 
cent dilution speeded up ammonification in 
batches without inoculation, but was of no 
advantage if inoculation was used. Dilution 
was, of course, a disadvantage because of 
greater difficulty of concentrating. 

Under aerobic rather than anaerobic condi¬ 
tions, the ammonification proceeded at about 
the same rate but the loss of ammonia was ex¬ 
cessive, often amounting to more than 50 per 
cent of the total ammonia. If the process is 
carried out in deep tanks, the system becomes 
anaerobic within a few hours because of the 
biological oxidation of the reducing sugar in 
the urine, and this condition of operation was 
recommended. 

The pH over the range encountered did not 
inhibit the bacterial action. No accessory nu¬ 
trients were necessary for the bacteria. 

The nitrogen content of urine can also be 
converted to ammonia by the enzyme urease 
instead of by bacteria. This has the advantage 
of requiring less time for the completion of the 
reaction and the disadvantages of being inhib¬ 
ited by a high pH and requiring dilution by 
10 per cent additional water. 

Soybeans contain urease which can be ex¬ 
tracted by mixing one part of soybean meal 
with ten parts of water for 1/2 to 1 hour with 
occasional agitation, and finally allowing the 
mixture to settle and drawing off the top liquid. 
The fineness of the bean meal is not important; 
roughly 20-mesh or finer is satisfactory. The 
meal which is left is not harmed and may be 
used as food. The mixing tanks preferably 
should be of ceramics or wood, since the salts 
of many metals have an inhibiting effect on 
the urease. No heating is necessary and the 
required agitation can be done with hand pad¬ 
dles if desired. The urease extract must be 



124 


PRODUCTION OF NITRIC ACID FROM URINE 


used within 48 hours from the time it is pre¬ 
pared and preferably the same day. 

One part of the urease extract is added to 
ten parts of urine and the temperature raised 
to about 30 C for best results. A higher tem¬ 
perature results in a faster reaction but also 
in greater loss of ammonia. The urease be¬ 
comes inactive at about 60 C. 

The urease becomes unreactive if the pH of 
the urine rises to 8.8. By the time the alkalin¬ 
ity reaches this figure the reaction should be 
practically complete. If for any reason it is 
not, the alkalinity can be reduced by bubbling 
carbon dioxide through the liquid. In fact, the 
optimum pH for the reaction is 7, and if car¬ 
bon dioxide is available, it is an excellent ma¬ 
terial for controlling the alkalinity. By bub¬ 
bling carbon dioxide through the mixture for 
5 minutes at approximately 30-minute inter¬ 
vals, the time required for the conversion will 
be reduced to about three quarters of that 
otherwise required. 

The enzyme process proceeds more rapidly 
when the pH of the solution is below 8. The 
bacterial process works faster at a pH above 
8. A combination of the two processes allows 
each to operate at its preferred pH and results 
in a faster reaction than when either reaction 
is used alone. The bacterial process is started 
exactly as the enzyme process by adding one 
part of urease extract to ten parts of urine. 
If the temperature is kept at about 30 C, the 
ammonification will be about 40 per cent com¬ 
plete in 1 hour and the pH will have risen to 
above 8. At this point, 10 per cent of fer¬ 
mented urine from a previous batch is added 
and the reaction allowed to go to completion. 

The approximate times for complete ammo¬ 
nification by these processes are: 

38 C 28 C 

Bacterial process 12 hr 24 hr 

Enzyme process 4 8 

Combination 2 4 

The ammonia solution obtained by either bac¬ 
terial or urease treatment of urine will con¬ 
tain about 1 per cent ammonia. This must be 
concentrated for subsequent use in making 
nitric acid or ammonium salts. A laboratory 
investigation of the stripping of converted 
urine was carried out in order to check the 


simple ammonia-water distillation calculations 
and to obtain some experience with regard to 
the foaming problem. This work showed that 
the standard ammonia-water equilibrium data 
can be used to calculate the result of distilla¬ 
tion of ammonia from the fermented urine. 
Addition of lime to the fermented urine be¬ 
fore distillation slightly increased the yield of 
ammonia; it seemed to have little effect on 
foaming. 

A plant design was worked out for the con¬ 
centration, which was unique in that construc¬ 
tion materials were limited to nonmetallic ma¬ 
terials, since metals were extremely scarce in 
China. 1 


23 4 BIOLOGICAL NITRIFICATION OF 
URINE 2 

The nitrogen in human urine may be con¬ 
verted to nitrates by subjecting it to the action 
of a mixed natural flora of nitrifying bacteria 
upon beds of crushed limestone coated with 
small amounts of soil. About 30 grams of ni¬ 
trate nitrogen may be obtained per cubic me¬ 
ter of bed per day. The effluent is a 1.75 per 
cent solution of calcium nitrate together with 
other urine salts. Efficiencies depend upon care 
of operation; under usual conditions about 75 
per cent recovery may be expected; but with 
adequate laboratory control this may be im¬ 
proved to 90 per cent or better. 

Nitrates are produced naturally in many 
soil and water systems. The conversion of am¬ 
monia to nitrate by bacteria takes place in two 
recognizable steps: (1) the oxidation of am¬ 
monia to nitrite by species of Nitrosomonas 
and Nitrosococcus, and (2) the further oxida¬ 
tion of nitrite to nitrate by members of the 
genus Nitrobacter. These organisms occur in 
practically all natural media and are particu¬ 
larly abundant in the aerated, surface layers 
of fertilized soils, on the upper few inches of 
slow sand sewage filters, and in shallow, lightly 
polluted surface waters. 

Previous methods of intensive nitrification 
of ammonia were reviewed and tested along 
with other promising processes. Some of the 
methods previously recomended for ammonia 






BIOLOGICAL NITRIFICATION OF URINE 


125 


did not apply to urine because of its limited 
nitrogen content, its chloride, carbonate, sul¬ 
fate, and phosphate content, its alkaline re¬ 
action after fermentation, and its high surface 
activity. 

The conditions for optimum activity of in¬ 
dividual species in pure culture vary widely, 
but in natural systems where a number of spe¬ 
cies are simultaneously active the following 
appear to be most favorable. 

1. A large surface area such as may be pro¬ 
vided by loose straw or peat beds, by cinders, 
charcoal crumbs, crushed rock, coarse sand, or 
crumbly soil. 

2. A supply of oxygen furnished by moving 
liquids or by diffusion of air into films of liquid 
on wetted surfaces; anaerobic conditions block 
nitrification. 

3. Moisture sufficient to maintain a film of 
water and nutrients over the slime of bacteria 
attached to surfaces of the solid medium. 

4. Moderate temperatures: systems adapt 
themselves to the prevailing temperatures, but 
nitrification appears to take place slowly at 
temperatures close to freezing; the optimum 
range of temperatures lies between 25 C and 
30 C. 

5. The presence of bicarbonates: nitrifying 
bacteria are autotrophic in their metabolism 
and utilize this source of carbon for cell syn¬ 
thesis. 

6. The presence of calcium or magnesium 
base in amounts slightly in excess of that re¬ 
quired to combine with the nitric acid formed. 
Porous limestone itself forms an excellent sur¬ 
face for the activity of nitrifiers. 

7. Favorable hydrogen-ion concentrations 
usually lying on the alkaline side of neutrality 
but varying with the condition of the system. 
Nitrification usually ceases at pH values below 
4.0 and above 10.3. 

8. Nitrifying systems with ammonium con¬ 
centration maintained at levels below 1,000 
ppm nitrogen. Activity usually begins earlier if 
lower concentrations are used. It is possible 
to raise the concentration as the system devel¬ 
ops, and in some organic-rich soils concentra¬ 
tions in excess of 1,000 ppm nitrogen may be 
nitrified. 

9. A system free of readily decomposed or¬ 


ganic matter. The presence of considerable 
quantities of soluble and readily available or¬ 
ganic matter makes possible the growth of 
competitive organisms. The metabolism of the 
nonnitrifying flora may produce anaerobic con¬ 
ditions and bring about the reduction of pre¬ 
formed nitrates and their loss as nitrogen gas. 
For this reason it is desirable that support 
material be inert to bacterial activity. 

In the system recommended, dilute urine 
was percolated over beds of %-in. limestone, 
lightly coated with activated nitrifying soil. 
After nitrification had begun the concentration 
of nitrogen in the system was built to an opti¬ 
mum level by adding ammonified urine to the 
effluent and recirculating the mixture over the 
beds. Chemical control of the system was ob¬ 
tained by observing the concentration of ni¬ 
trite. Good conditions are indicated by traces 
or total absence of nitrite, unsatisfactory con¬ 
ditions by rising nitrite concentrations. This 
measurement provided a convenient indication 
for increasing or decreasing the rate of feeding 
urine. 

From the performance of experimental beds, 
it was found that approximately 0.3 cu m of 
crushed limestone per capita was required. 
This assumed that the average nitrogen yield 
of urine lay between 8 and 12 grams per day 
per person. Beds 0.5 m deep were used, but 
deeper beds may be used. The practical limit 
is determined by the accumulation of silt 
washed from the upper layers of stone into 
grids and lower layers of the bed. Ventilation 
is adequate in beds 1.0 m deep and possibly 
deeper if existing soil is removed. Small lime¬ 
stone lumps gave the best results because they 
presented the maximum active surface. If 
finer than *4 in. to % in., however, they tended 
to clog after a few weeks’ operation and ven¬ 
tilation problems developed. The quantity of 
nitrifying soil used varied with the soil type, 
but represented approximately 5 per cent by 
weight. The proportion of soil must be deter¬ 
mined empirically by finding how much will 
adhere to samples under conditions of recircu¬ 
lation. It is advisable to prepare the nitrify¬ 
ing soil as soon as operations can be started, 
since about six to eight weeks will be required 
to obtain an active soil. 



126 


PRODUCTION OF NITRIC ACID FROM URINE 


Beds should rest upon false bottoms to per¬ 
mit rapid draining and to prevent the forma¬ 
tion of pools. If stagnant zones developed, de¬ 
nitrification and loss of nitrogen occurred. A 
further advantage was the better ventilation 
of beds resting on grid work or other false 
bottoms. Such beds are less likely to become 
waterlogged by rain storms. The effluent of 
the beds was recirculated at rates of 150 to 
300 liters per cubic meter per day, and am¬ 
monified urine was added to the recirculating 
system at rates of 4 to 6 liters per cubic meter 
per day. Reservoir bottoms were kept small so 
that as much of the liquid as possible would 
be on the beds. Practically, this depended upon 
rates of evaporation and the frequency with 
which the volumes were replenished—a res¬ 
ervoir volume of approximately 40 liters per 
cubic meter of bed was adequate. 

The beds may be operated as continuous sys¬ 
tems. In order to obtain ammonia-free efflu¬ 
ents, however, a period of recirculation with¬ 
out added urine must be allowed. It was rec¬ 


ommended that the bed be fed urine through 
the day and allowed to oxidize the final addi¬ 
tions of ammonia during 6 to 8 hours of the 
night, and that the unneeded nitrified effluent 
be drawn off in the morning before feeding is 
resumed. 

If possible, the plant should be sheltered with 
a raintight roof. The bed will be less subject 
to diurnal fluctuations in temperatures and 
evaporation losses will be reduced. No damage 
to the nitrified flora occurs from rains or tem¬ 
porary flooding of the beds beyond the dilution 
of the effluent. The bacteria will retain their 
activity. Drying of the bed, however, is fol¬ 
lowed by a drop in activity extending over a 
week or more. Should this occur, it is not neces¬ 
sary to remake the bed with fresh earth, as 
the dried bed will gain its full activity in a 
shorter time than new beds required to come 
to full activity. 

Fields for solar evaporation or equipment 
must be provided for evaporating approxi¬ 
mately 3 liters of effluent per person per day. 



Chapter 24 

SUPPRESSION OF DUST AROUND ARTILLERY EMPLACEMENTS 


241 INTRODUCTION 

T he firing of field artillery pieces over dry 
ground raises a considerable cloud of dust, 
which is a distinct disadvantage because it ob¬ 
scures the gunner’s vision so that he cannot 
observe the impact of the projectile and correct 
his aim in succeeding rounds, and because it 
reveals the gun position to enemy observers. 
This condition is aggravated by the practice of 
digging in the fieldpiece in order to present a 
lower silhouette. Often the muzzle of the gun is 
only 1 to 2 ft above the ground. This digging in 
results in loose dirt around the gun and by plac¬ 
ing the muzzle near the ground greatly in¬ 
creases the blast on the dirt. 

An investigation of methods of suppressing 
the dust was carried out along two lines: (1) a 
chemical treatment that could be applied readily 
to the dust and which would bind it to such an 
extent that it would not be disturbed by the 
blast, and (2) a portable mat of suitable size 
and material so that when laid on the ground in 
front of a gun it would withstand the blast and 
allay the dust. a 

242 CHEMICAL TREATMENT OF GROUND 2 

A number of common chemicals that might 
be suitable for binding the loose surface dirt 
were tested. These chemicals included casein, 
sodium alginate, cane sugar molasses, corn 
syrup, calcium chloride, library paste, ordinary 
glue, linseed oil, sodium silicate, polyvinyl alco¬ 
hol, clear automobile lacquer, a quick-set 
gypsum (Hydrostone). Water solutions or 
emulsions were considered to be most desirable, 
and wetting agents would be needed to gain 
penetration. Wetting agents suggested were: 
abietic acid, Aerosol OS and OT, Dreft, Nacco- 
nol F and NR. To form emulsions various pep¬ 
tizing media were suggested: monoethanola- 

a Division 2 worked on this problem from the point of 
view of developing improved blast deflectors, which 
would disperse the blast sufficiently to materially re¬ 
duce the dust raised. 


mine and triethanolamine, cream of tartar, 
sodium hydroxide. 

Artificial soils composed of mixtures of finely 
divided clay (Drilloid, or drilling mud clay) and 
fine sand were prepared and placed in shallow 
glass baking dishes. An air gun was built to 
operate on compressed air at approximately 100 
psi pressure, and fitted with a %-in. orifice and 
quick-opening valve. The surface of the artificial 
soil bound with a given chemical was blasted 
with the air gun. The binders were rated accord¬ 
ing to their ability to withstand the blast of the 
laboratory air gun and the most promising ones 
were tested on natural ground subjected to the 
muzzle blasts of 76-mm and 90-mm guns. 

Wafer was first tried with the addition of 
only a wetting agent to obtain penetration 
(Aerosol OT in a concentration of 0.1 per cent 
was the best wetting agent for this use). This 
was found unsatisfactory unless impractically 
large amounts were applied. 

The primary purpose of the deliquescent ma¬ 
terials (black strap molasses, corn syrup, cal¬ 
cium chloride) was to retain moisture. As might 
be expected, aqueous solutions of these ma¬ 
terials were little, if any, better in binding 
power than water alone. 

These tests indicated that it was necessary 
to bind the upper surface of the ground to form 
a slab strong enough to resist the tension, com¬ 
pression, and shear stresses induced in it by the 
shock of the blast. A high endurance limit was 
essential. 

Casein, library paste, and ordinary glue were 
tried, but found to give weak crusts that were 
very slow in attaining strength. They were no 
better than water with wetting agent, failing 
after a few tests from the laboratory gun. Poly¬ 
vinyl alcohol was difficult to put into water solu¬ 
tion at room temperature and was very slow- 
setting unless heat was applied. An attempt to 
speed the set by the addition of hydrogen per¬ 
oxide showed no appreciable benefit. An emul¬ 
sion of linseed oil and water was made with 
cobalt resinate added to speed the attainment 
of strength by the linseed oil. When sprayed on 



127 



128 


SUPPRESSION OF DUST AROUND ARTILLERY EMPLACEMENTS 


the soil, the emulsion broke down and failed to 
wet the dust. All the wetting agents were tried, 
but none was satisfactory either in obtaining 
penetration or stopping the breakdown of the 
emulsion. 

Alginates (Keltex and Kelgum) gave fairly 
good results in the laboratory and were deemed 
worthy of full-scale tests. 

Excellent laboratory results were obtained 
with sodium silicate, a 40 per cent clear lacquer 
with a 60 per cent lacquer thinner solution, and 
Hydrostone. Philadelphia Quartz Company D 
Brand sodium silicate was used, which con¬ 
tained about 44 per cent sodium silicate and 56 
per cent water. Slight reduction of the water 
caused the liquid to solidify into a hard, very 
strong mass. Penetration was obtained by using 
0.1 per cent Aerosol OT in the water used to 
dilute the sodium silicate as obtained from the 
manufacturer. It was found that a 1:1 solution 
by weight (1 part D Brand sodium silicate and 
1 part 0.1 per cent Aerosol OT water solution) 
penetrated well, had excellent strength after 
being allowed to set 1 hour, and withstood the 
air-gun blasts well. One hundred blasts did not 
disturb the soils in the pans. Philadelphia 
Quartz Company GC Brand powder is the dehy¬ 
drated form of D, and has the advantage of 
better transportability. 

Various percentages of lacquer were tried in 
the laboratory. A volume mixture of 40 per cent 
lacquer and 60 per cent thinner was found to 
form a dense, hard crust about % in. thick on 
a wide variety of sand-clay mixtures. One gal¬ 
lon of the mixture per square yard of treated 
surface appeared satisfactory. Repeated blast¬ 
ings up to 75 times with the air gun in the 
laboratory were withstood without visible dam¬ 
age to the soils. A disadvantage for this ma¬ 
terial was that about 8 hours were required 
from time of application until the material had 
dried sufficiently for testing. 

Various gypsum plasters were added in vary¬ 
ing amounts to artificial soils in the laboratory. 
Those tried were art plaster, dental plaster, 
moulding plaster, and Hydrostone. Of these the 
most promising was Hydrostone, and it was 
tested most thoroughly. The manufacturers 
(United States Gypsum Company) claimed a 
tensile strength of 850 psi and compressive 


strength of 11,000 psi for a normal consistency 
neat plaster paste (about 32 per cent water by 
weight). Such a plaster was too stiff to permit 
addition to soil, but increasing the water to 60 
per cent by weight gave good workability and 
the plaster-soil mix was hard in 1 hour after 
application. In the laboratory, as small amounts 
of plaster as 10 per cent of the weight of the 
soil gave excellent resistance to air gun blasts. 

In full-scale tests with a 76-mm tank de¬ 
stroyer gun at Camp Hood, Texas, the sodium 
alginates formed gums that were too weak 
to withstand blasts even from high muzzle 
heights, and were destroyed by the first round. 

Sodium silicates formed crusts that with¬ 
stood the muzzle blast fairly well. The Phila¬ 
delphia D Brand silicate diluted with 1 part of 
water (to which was added 0.1 per cent Aerosol 
OT clear) when sprayed from a knapsack-type 
sprayer at the rate of 1 gallon of solution per 
square yard of ground surface formed an excel¬ 
lent crust 1 hour after application. The crust 
withstood many rounds from muzzle heights 4 
ft to 7 ft above the treated soil, but was de¬ 
stroyed by 10 to 15 rounds at low muzzle height 
(15 in.) 

It was concluded that sodium silicate would 
not form a sufficiently strong crust to with¬ 
stand continued firing at low muzzle height 
even when muzzle brakes were used on a 76-mm 
gun, and would be totally unsatisfactory for 
use without muzzle brake or under rounds from 
larger guns. Sodium silicate seemed to possess 
sufficient merit as a binding agent to use it on 
areas of low blast intensity if a more feasible 
method could not be found for alaying dust. 

Contrary to laboratory tests, the clear lacquer 
was of no advantage in laying dust of the nat¬ 
ural soil treated at Camp Hood. The first round 
from a 76-mm gun with muzzle height of 17 in. 
and without muzzle brake completely destroyed 
the treated surface and raised great clouds of 
dust as though the soil had been untreated. 

The Hydrostone was spread over the loose 
soil as uniformly as possible and raked in with 
a garden rake to a depth of 1 to 2 in.; then 
water containing 0.1 per cent Aerosol OT was 
poured on the mixture until an amount equal to 
0.6 per cent of the weight of Hydrostone had 
been added. After 1 hour two rounds from a 



BLAST MATS 


129 


3-in. gun without muzzle brake and at muzzle 
height of 15 in. were fired over the treated posi¬ 
tion. The first round cracked and broke the 
surface, the second destroyed it and raised large 
white dust clouds. The position used in the test 
was on a side hill slope (about 6 per cent). The 
water ran and collected in pools in the depres¬ 
sions leaving the summits with insufficient 
water to hydrate the plaster. The low places 
were strong and undisintegrated by the two 
rounds, but sufficient high spots were weak, 
chalky, and dusty underneath to make the 
method unsatisfactory. 

These tests demonstrated that none of the 
tried chemical treatments resulted in crusts 
sufficiently strong to withstand blasts generated 
in direct fire from prepared gun positions 
whether or not muzzle brakes were used. 

243 BLAST MATS 3 

Preliminary tests of cotton canvas mats 
15 x 18 ft for dust suppression were made by 
the Tank Destroyer Board at Camp Hood, 
Texas. The canvas had a tensile strength of 345 
pounds per in. width. These tests showed that 
the mats markedly reduced the amount of dust 
raised and decreased the time of obscuration of 
the target. The canvas mats, however, were not 
of sufficient strength to withstand continued 
firing at low muzzle heights with the 3-in. or 
76-mm guns, with or without muzzle brake. A 
search was, therefore, made for a material 
which was strong enough for this use. 

243 1 Nylon 

Nylon cloth suggested promise because of the 
known high strength and light weight of Nylon. 
Because of its fairly low melting point, how¬ 
ever, there was doubt as to the effect of the 
heat from the blast. Preliminary tests were 
made by sewing 38-in. wide strips of Nylon 
duck to a canvas mat and subjecting it to the 
blast from a 76-mm gun without muzzle brake, 
using a muzzle height of 15 in. This Nylon 
weighed about 10 oz per sq yd and had a tensile 
strength of 800 pounds per in. width. It carried 
the du Pont code number NFD-191/2. After 
ten rounds the seams were loosened and the 


Nylon somewhat scorched and glazed at the 
area of maximum blast. Further tests with a 
3-in. gun at 10-in. muzzle height aggravated 
these effects indicating that the material was 
strong enough but that it was adversely affected 
by the heat. The tests emphasized the need for 
strong seams and grommeting, grommets being 
necessary for pegging the mat to the ground. 

The Army Ordnance Department had a full- 
size (18 x 24 ft) mat made from a double thick¬ 
ness of the same Nylon duck. 1 Seams were lock- 
stitched with Nylon thread and the two thick¬ 
nesses of cloth were quilted together every 6 
in. Grommets were placed every 3 ft over the 
entire mat, as shown in Figure 1. Tests of this 
mat verified previous conclusions. The mat was 
strong enough until weakened by the heat, after 



Figure 1. Nylon duck blast mat under 76-mm 
gun. 

which it tore. The effect of the heat was par¬ 
ticularly severe when flashing ammunition was 
used at low bore heights. 

It was apparent that if advantage was to be 
taken of the good properties of the Nylon, some 
surface protection must be given to it. Two 
mats were therefore fabricated, one of a double 
thickness of the 19-oz Nylon, with the top sur¬ 
face coated with Vinylite; the other of a single 
thickness of 13-oz Nylon with the top surface 
coated with Perbunan synthetic rubber. 

The Vinylite-coated Nylon was considerably 
better than the uncoated Nylon. When the 
90-mm gun was used at a bore height of 12 in., 
however, the Vinylite coating was gradually 
removed until the Nylon was exposed and fuzed 
and the mat torn. 





130 


SUPPRESSION OF DUST AROUND ARTILLERY EMPLACEMENTS 


The Perbunan-coated Nylon was the best ma¬ 
terial tried. It withstood six rounds with the 
76-mm gun and 14 rounds with the 90-mm, ten 
of the latter at a bore height of 12 in. The rub¬ 
ber satisfactorily protected the Nylon surface 
from the heat. Failure occurred from holes 
punched in the mat by stones underneath. The 
heavier Nylon, particularly if used in two thick¬ 
nesses, would probably have given better 
results. 

2432 Vinylite 

Preliminary tests with strips of sheet Viny¬ 
lite sewed to canvas indicated the material was 
satisfactory if proper seams and grommets 
were used. This material was 0.08 in. thick, 
weighed about 4i/ 2 pounds per sq yd, and had 
a tensile strength of 110 pounds per in. width. 
Although the tensile strength was low, the 
elongation before break was 350 per cent, 
which resulted in a large part of the force of 
the blast being absorbed before the breaking 
point was reached. This material carried the 
Bakelite Corporation code number F.6988. 

A full-size mat was made of this material 
except that the thickness was reduced to 0.06 
in. in order to keep the weight within the de¬ 
sired 31/2 pounds per sq yd. This material was 
not so good as the rubber-coated Nylon, but it 
was one of the best tried. In the tests it with¬ 
stood 17 rounds of the 76-mm and 90-mm guns, 
but was destroyed by stone cuts when used with 
the 90-mm gun at a bore height of 15 in. 

In order to determine whether there was any 
advantage to mats which allowed air to pene¬ 
trate them, a mat was woven from 1-in. Viny¬ 
lite strips Vie in. thick. This mat, however, was 
too heavy (12 pounds per sq yd) and the woven 
surface apparently offered too much resistance 
to the blast. One round of the 90-mm gun at a 
bore height of 11 in. destroyed the mat. 


243 3 Neoprene 

Since Neoprene has greater tensile strength 
and abrasion resistance than Vinylite, a mat 
was made of sheet Neoprene 0.06 in. thick. The 
results, however, with this mat were not so 


good as with the Vinylite. The mat was de¬ 
stroyed with the 3-in. gun at a bore height of 
12 in. The poor results may have been due to 
a rather rough surface, as opposed to a glossy, 
smooth surface on the Vinylite, which offered 
more resistance to the blast. 

A mat made by sealing a loosely woven 
elastic cotton stockinet between two layers of 
Neoprene gave better results. The stockinet 
apparently furnished additional tear resistance 
to the Neoprene. Since the conditions of firing 
were not the same as for the Vinylite, a com¬ 
parison of the two is difficult, but this mat was 
probably as good and would have given better 
results if it had had a smooth surface. 


24 3 4 Fabrication 

As stated earlier, the fabrication of the mat 
is as important as the material used. The first 
mats tested failed at the seams or grommets 
rather than in the material itself. The blast 
broke the thread of any exposed stitching, even 
when Nylon thread was used. To avoid this, 
cementing or heat sealing of the seams was 
used whenever possible. With fabrics, which 
required stitching, triple stitching with Nylon 
thread was used. Lock stitches were essential. 
All stitching was protected from the blast by 
covering it with a strip of Vinylite, rubber, or 
other suitable material. 

Two types of grommets were found satis¬ 
factory. On the Vinylite mat the area of the 
grommet was reinforced by cementing on addi¬ 
tional thicknesses of the mat material, and 
the whole clamped between two 6-in. diameter 
16-gauge steel plates. The plates were held by a 
%-in. pipe nipple through the center of the 
plates with nuts on each end. On the two Neo¬ 
prene mats two 6-in. diameter steel plates with 
%-in. center holes were placed on each side of 
the mat and held by six stove bolts %-in. in 
diameter. 


244 CONCLUSIONS 

Blast mats are more satisfactory for sup¬ 
pressing dust around artillery emplacements 
than is chemical treatment of the ground. With 



CONCLUSIONS 


131 


the best chemical found, the preparation of a 
position required about 250 pounds of sodium 
silicate and 250 pounds of water. A sprayer 
was also necessary. A blast mat weighing less 
than 150 pounds can be used repeatedly in 
different positions and will withstand greater 
blast. 

While the mats tested could not stand up 
under firing at very low bore heights, they very 
substantially reduced the dust and would be 
practical when bore heights above the mini¬ 


mum are used. Trials would have to be made to 
determine what height could be used continu¬ 
ally with the best mats, but in all probability 
they would be satisfactory at bore heights of 
18 in. or higher with the 76-mm gun and 21 to 
24-in. or higher with the 90-mm gun. If im¬ 
proved blast deflectors are developed, the mats 
may be satisfactory at any muzzle height used. 

It is estimated that for 3-in, 76-mm, and 
90-mm guns blast mats should be about 
18 x 24 ft. 





Chapter 25 

MANUFACTURE OF HYDROGEN PEROXIDE 


251 SUMMARY 

A t the request of NDRC, an investigation 
- of methods of production of concentrated 
hydrogen peroxide was undertaken. Shortly 
after the investigation was started, information 
on the German processes became available, and 
the program was curtailed. A general report 
on hydrogen peroxide technology was prepared. 

Small-scale laboratory work showed the 
feasibility of producing exceptionally pure 60 
to 65 per cent hydrogen peroxide by means of a 
glow discharge in water vapor at 0.15 to 0.32 
mm Hg pressure. A condenser cooled with 
liquid air is required, and the power require¬ 
ment is relatively high. 

Hydrogen peroxide at strengths up to 90 per 
cent was obtained by a photochemical syn¬ 
thesis using ultraviolet radiation of a mixture 
of hydrogen and oxygen carrying a trace of 
mercury vapor. This process operated well at 
atmospheric temperature and pressure with a 
power consumption about twice that of the 
commercial electrochemical methods. 

An investigation of the application of mod¬ 
ern fluidized powder techniques to the old 
barium peroxide process for hydrogen peroxide 
indicated the possibility of a cyclic continuous 
process involving decomposition of barium 
nitrate, oxidation to the peroxide, reaction with 
acid, and recycling of the barium. Estimated 
power, fuel, and material costs for such a 
process are extremely low. 

25 2 INTRODUCTION 

One of the most important chemical develop¬ 
ments by the enemy during World War II was 
the German use of concentrated hydrogen per¬ 
oxide as a source of energy and oxygen in vari¬ 
ous new munitions. Peroxide was used as a 
rocket fuel in the Hs-293 glide bomb, in the 
Me-163 jet-propelled aircraft, and in various 
assist-take-off devices for aircraft. It was em¬ 


ployed as a propellant in launching the V-l 
“flying bombs,” and as a source of power for a 
turbine to drive the fuel pumps of the German 
V-2 weapons. Wakeless long-range peroxide- 
driven torpedoes were under development at 
Kiel at the close of the war. Perhaps the most 
important development was a peroxide-driven 
submarine capable of 25 knots under water; the 
introduction of this submarine in large num¬ 
bers might have disrupted shipping to England. 

The interest of the United States in military 
applications of peroxide became keen in the 
winter of 1944-1945, at a time when supplies 
of commercial peroxide in this country were 
seriously short. Section 11.2 was asked in 
February 1945 to investigate methods of manu¬ 
facture of concentrated peroxide and proceeded 
with an experimental program covering both 
manufacturing methods and means for con¬ 
centrating dilute aqueous solutions. These 
studies were barely under way when the Rhine¬ 
land was occupied and detailed reports of Ger¬ 
man manufacturing techniques began to come 
in. At about the same time, an American 
manufacturer (Buffalo Electrochemicals Co.) 
volunteered information concerning their de¬ 
velopment of a pilot plant for producing 90 per 
cent solutions of peroxide by a distillation 
process starting with commercial 30 per cent 
solutions, and an English concern (Messrs. La- 
porte, Ltd.) constructed a pilot plant of a simi¬ 
lar type. Because of these developments the 
NDRC-sponsored program was not pushed, and 
only two small contracts were continued until 
the fall of 1945. 

As a basis for planning the program con¬ 
templated in early 1945, a study was made of 
the possible methods of manufacture, the vari¬ 
ous military uses, and the existing technical 
information relating to hydrogen peroxide. 
This study was described in a general report 2 
which was issued in the summer of 1945, and 
which may be referred to for a summary of 
the state of the art at that time. 


132 


PHOTOCHEMICAL AND ELECTRIC DISCHARGE METHODS 


133 


25 3 PRODUCTION OF HYDROGEN 

PEROXIDE BY PHOTOCHEMICAL AND 
ELECTRIC DISCHARGE METHODS 4 

25,31 Introduction 

At the time the German use of hydrogen per¬ 
oxide was first disclosed, it was considered 
likely that the concentrated solution was ob¬ 
tained directly by a process involving electric 
discharge in water vapor at low pressure. Al¬ 
though the large-scale German production was 
later found to have been obtained by distilla¬ 
tion of 30 per cent solution produced by elec¬ 
trolysis, a pilot plant based on the electric dis¬ 
charge method 2 was located at Elektroche- 
misches Werke Miinchen at Hollriegelskreuth 
and is described in intelligence reports. The 
Germans appear to have thought the process to 
be entirely practical for production of strong 
peroxide under conditions of high labor costs 
and low power costs. Before these facts were 
known, NDRC had initiated an exploratory 
study of the electric discharge and related 
methods. 

25.3.2 Q] ow Discharge in Water Vapor 

The glow discharge apparatus consisted of 
a 25-mm glass tube 176 cm between aluminum 
electrodes. Water vapor was introduced through 
a controlled capillary leak and traversed 35 
cm of the discharge tube before being drawn 
off through a liquid air trap. Pressure was 
maintained in the range 0.1 to 0.6 mm Hg. The 
primary of the transformer was supplied with 
60-c 110-v alternating current, and the second¬ 
ary leads connected directly to the discharge 
tube electrodes, with a maximum secondary 
voltage of 14,000. The amount of water vapor 
fed was measured, and the condensate obtained 
in the liquid air trap was weighed and ana¬ 
lyzed for hydrogen peroxide. 

Optimum results were obtained with a 
steady full discharge, rosy pink in color, with 
a power input to the primary of 300 to 380 w, 
a secondary voltage of 600 to 650, and at pres¬ 
sures of 0.15 to 0.32 mm Hg. The condensate 
obtained consisted of 60 to 65 per cent hydrogen 
peroxide and 35 to 40 per cent water. 


Complex ionization processes occur in the 
glow discharge resulting in uncharged atomic 
hydrogen and hydroxyl radical. Losses are 
believed to be due to combination of hydrogen 
atoms on the walls of the tube to produce 
molecular hydrogen, and to recombination of 
hydrogen atoms and hydroxyl radicals to form 
water. Hydrogen peroxide is presumably 
formed by direct combination of hydroxyl 
radicals: 

0H + 0H-^H 2 0 2 

Unless surface is provided at a temperature 
about that of liquid air the hydroxyl radicals 
do not condense and no peroxide is formed. 
This is believed to be due to the volatility of 
hydroxyl radicals, which is probably about that 
of hydrogen chloride. Condensation must occur 
promptly or the hydroxyl radicals react in the 
vapor phase to produce molecular hydrogen 
and oxygen directly. It is necessary to have 
both rapid condensation and cooling to about 
liquid air temperatures; rapid cooling with a 
solid carbon dioxide trap gives no peroxide 
product. The addition of oxygen to the water 
vapor feed did not improve the peroxide yield, 
as had been thought possible due to reaction 
of oxygen with hydrogen atoms. If it is as¬ 
sumed that a hydroxyl radical has the same 
chance of combining with another hydroxyl 
radical to form peroxide as it has of reacting 
with a hydrogen atom to form water, then the 
product should consist of an equimolal mix¬ 
ture of water and peroxide, containing 65 per 
cent hydrogen peroxide by weight. This checks 
the observed maximum concentrations of 60 to 
65 per cent. 

With the laboratory equipment employed the 
power consumed was very large in relation to 
the amount of peroxide formed. It is estimated, 
however, that only about 10 per cent of the 
power input was actually expended in the dis¬ 
sociation of water vapor. On this basis the ex¬ 
perimental result of 0.013 gram of 55 per cent 
peroxide solution per minute with a total 
power input of 330 watts corresponds to 35 
kilowatt-hours per pound 100 per cent hydro¬ 
gen peroxide. This compares with 28 kilowatt- 
hours per pound reported by the Germans 2 
for their electric discharge process, and 6 to 8 
kilowatt-hours per pound for the commercial 



134 


MANUFACTURE OF HYDROGEN PEROXIDE 


electrochemical processes. It is estimated that 
the theoretical minimum for the glow dis¬ 
charge process is about 3.6 kilowatt-hours per 
pound. 

The glow discharge process has the advan¬ 
tages of requiring only water as raw material 
and of producing a very pure product at rela¬ 
tively high concentrations. The disadvantages 
are the relatively high power requirements and 
the low pressure at which the operation must 
be carried out. 


25.3.3 Photochemical Synthesis 

The photochemical process involves direct 
synthesis from hydrogen and oxygen at at¬ 
mospheric temperature and pressure. The re¬ 
action is accomplished by illuminating the 
mixed gases containing a trace of mercury 
vapor with ultraviolet light of wavelength 
2,537 A. The gases are saturated with mer¬ 
cury vapor at room temperature, the resulting 
mercury concentration being sufficient to ab¬ 
sorb almost all the incident radiation in a light 
path of a few millimeters. The light quanta ab¬ 
sorbed cause the formation of activated mer¬ 
cury which reacts with hydrogen molecules to 
produce atomic hydrogen. The atomic hydro¬ 
gen combines with oxygen to form hydrogen 
peroxide. Losses are encountered due to re¬ 
combination of hydrogen atoms on the walls 
of the vessel, and to deactivation of mercury 
by oxygen. 

In the experiments performed, dry gaseous 
hydrogen and oxygen were supplied through 
calibrated flowmeters, mixed, and the mixture 
passed over mercury at 100 C. The gases were 
then cooled to room temperature and passed 
through a 20-mm ID quartz tube exposed for 
a length of 25 cm to radiation from a mercury- 
vapor lamp. The condensable products were 
collected in a liquid air trap specially designed 
to eliminate fog formation. The quantum input 
to the reaction tube was calibrated by using 
uranyl oxalate as an actinometer, and the data 
on peroxide yield then combined with the 
quanta input obtained in this way to give the 
“quantum yield.” Values of quantum yield cal¬ 
culated by this procedure were 0.5 or less. If 


the reaction between oxygen and atomic hydro¬ 
gen is 

H + 0,->H(X 

and H0 2 + H0 2 H 2 0 2 + 0 2 

or H0 2 + H->H 2 0 2 . 

the quantum yield should be unity. The lower 
values obtained are believed to be due to the 
formation of ozone, which would not only con¬ 
sume quanta, but would destroy peroxide 
directly. 

With the straight reaction tube and the 
straight lamp the best results were obtained 
using a ratio of hydrogen to oxygen of 3.2. 
With this ratio of the two gases both total 
mols of peroxide produced and peroxide con¬ 
centration in the condensate increased with in¬ 
crease in total gas flow rate up to the maximum 
rate employed of 5,000 cc per minute. Under 
these conditions the product concentration was 
74 per cent, and the production was 0.017 
gram mol per hour. 

As in the case of the glow discharge ex¬ 
periments, the observed power consumption 
was very high. Based on the fraction of the 
total ultraviolet light absorbed by the reaction 
tube, the observed power consumption was 
estimated to be 14 kwh per lb 100 per cent 
hydrogen peroxide. Based on the quantum 
energy of 2,537 A light and a quantum yield 
of 0.5, the theoretical power consumption is 
3.6 kilowatt-hours per pound. It seems proba¬ 
ble that with proper design the process would 
operate with a power consumption less than 
for the glow discharge method, but perhaps 
greater than for the electrochemical processes. 
It has the advantage of not requiring liquid air 
for the condenser, and of producing peroxide 
at concentrations as high as 85 to 90 per cent 
directly. The disadvantages are the mercury 
contamination and the necessity of cooling and 
recirculating large quantities of gas. 


25 4 CYCLIC REDUCTION AND OXIDA¬ 
TION OF 2-ETHYLANTHRAQUINONE 

In the spring of 1945 it was learned that the 
Germans had developed a process for manu¬ 
facturing hydrogen peroxide by the cyclic re¬ 
duction and oxidation of 2-ethylanthraquinone, 



APPLICATION OF FLUIDIZED POWDER TECHNIQUES 


135 


and were, in fact, proceeding with the installa¬ 
tion of very large plant capacity based on this 
method. An analogous method using azobenzene 
had previously been developed in the United 
States, but had not been adopted commercially. 

Because of this Section’s interest in methods 
of manufacturing hydrogen peroxide, NDRC 
Division 9 agreed to sponsor a preliminary 
laboratory study of the reactions involved in 
the German process. The laboratory work 3 
demonstrated that the cyclic process gave 
quantitative yields of hydrogen peroxide, and 
that the cycle may be repeated many times 
without significant decrease in yield. An im¬ 
portant development of this study was the 
demonstration that by using tetrahydro-2- 
ethylanthraquinone it is possible to obtain 
about twice the yield of hydrogen peroxide per 
cycle as when 2-ethylanthraquinone is used. 


25 5 APPLICATION OF MODERN 

FLUIDIZED POWDER TECHNIQUES 
TO THE BARIUM PROCESS 

2551 Introduction 

Although dilute solutions of hydrogen per¬ 
oxide have been produced by the barium proc¬ 
ess for more than a century, the electrolytic 
processes, introduced some forty years ago, 
proved to be more economical; in the spring 
of 1945 only about 13 per cent of United States 
production was by the barium process. 

The barium process has been operated with 
various modifications, but generally involves 
first the production of barium oxide by de¬ 
composition of the carbonate or nitrate and 
subsequent oxidation of the oxide to the per¬ 
oxide in a stream of air (or oxygen) at about 
600 C. The barium peroxide is then treated 
with sulfuric acid to form hydrogen peroxide 
and permit the removal of barium as the in¬ 
soluble sulfate. The barium sulfate by-product, 
though not a high-priced chemical, has suffi¬ 
cient value to make the process competitive 
for the production of hydrogen peroxide in 
amounts corresponding to the market for bari¬ 
um sulfate. 

There are obvious possibilities of modifying 
this process by recirculating the barium and 


so eliminating the economic dependence on the 
sale of the barium by-product. Sulfuric is the 
preferred acid for reaction with the barium 
peroxide, since the resulting hydrogen peroxide 
is purer and more stable than when nitric acid 
is used. The nitrate is the preferred salt to use 
in producing barium oxide, since the product 
is in the desired porous form, making the 
oxidation to the peroxide relatively simple. In 
order to complete the cycle various steps may 
be employed. The sulfate may be converted to 
the chloride and this in turn converted to the 
nitrate by double decomposition with sodium 
nitrate. Much work has been done on the use 
of barium carbonate, with carbon dioxide em¬ 
ployed to react with barium peroxide to 
produce hydrogen peroxide. Decomposition of 
the precipitated sulfate has not proved prac¬ 
tical, and decomposition of the carbonate has 
required special techniques to produce the 
porous form of barium oxide. 

It seems evident that the lack of commercial 
success of the various cyclic barium processes 
for hydrogen peroxide is due mainly to the 
difficulty and expense of handling reacting 
solids at high temperature levels. If the decom¬ 
position of either the nitrate or the carbonate 
could be simplified, the cost of hydrogen per¬ 
oxide by the barium process could be reduced 
substantially. Furthermore, if it could be made 
cyclical, the process would not depend on the 
market for precipitated barium sulfate, which 
now represents 25 to 30 per cent of the value 
of the two products. For these reasons an 
attempt has been made to apply the relatively 
new fluidized powder techniques to the prob¬ 
lems of barium nitrate decomposition and ba¬ 
rium oxide oxidation at high temperatures, 
with a cheap cyclic process as the objective. 


2S.5.2 Application of Fluidized Powder 
Technique 

By the phrase “fluidized powder technique” 
is meant a continuous method of contacting a 
gas and a finely divided solid. The mass of 
powder “floats” in a stream of gas passing 
vertically, powder concentrations high enough 
to produce mixture densities of 20 to 50 lb per 




136 


MANUFACTURE OF HYDROGEN PEROXIDE 


cu ft, or even greater, being attainable. Be¬ 
cause of the turbulence of the stream the churn¬ 
ing bed of powder tends to be mixed rapidly, 
and the gas is brought into intimate contact 
with the large surface of the solid. Both gas 
and powder may be fed and withdrawn con¬ 
tinuously. 

In order to explore the applicability of this 
technique to the barium peroxide process, ex¬ 
periments were carried out in two laboratory 
reactors 1% and 2 in. ID respectively, each 4 
ft tall. These were made of alloy steel and 
electrically heated to controlled temperatures. 
The powder could be fed continuously either at 
the top or bottom. The hot gas leaving the top 
passed to a cyclone separator from which solid 
fines were recovered. In tests of barium nitrate 
decomposition the nitrogen oxides were ab¬ 
sorbed by concentrated sulfuric acid in a train 
of absorption tubes. The gas velocity in the 
heated reactor was kept within the range of 1 
to 1.5 fps (superficial). The gases used were 
oxygen or dry air free from carbon dioxide. 

The most important purpose of the tests was 
to determine the behavior of the suspended 
bed of powder, i.e., the “fluidization” and re¬ 
action rate characteristics. Satisfactory fluid¬ 
ization of both oxides and the nitrate was ob¬ 
tained at room temperature. As the tempera¬ 
ture was raised to 300 C, however, the oxide 
particles tended to agglomerate and settle out, 
allowing the gas to channel up through the bed 
with very little mixing. This effect was due 
to the fact that the barium oxide, reported to 
have a melting point of 1923 C, became slightly 
sticky at quite a low temperature. 

In order to avoid this difficulty an inert 
carrier was introduced in the form of pow¬ 
dered, fused magnesia or a powdered tertiary 
barium phosphate. Both of these gave satis¬ 
factory fluidization, although the phosphate 
showed some tendency to cling to the walls 
and settle out. In a typical experimental test 
the carrier was introduced first and the barium 
nitrate then added continuously at the maxi¬ 
mum rate compatible with good fluidization 
characteristics. In this way the capacity for 
barium nitrate decomposition, at 800 C, was 
found to be about 7.6 pounds per hour per 
square foot of cross-sectional area in the 2-in. 


reactor. Since the wall effect and tendency of 
the powder to bridge across the tube is much 
less in large reactors, the capacity may be ex¬ 
pected to be greater in reactors of commercial 
size. The nitrate decomposition reaction was 
very slow at 400 C but was very rapid and 
essentially complete at 800 C. Best results 
were obtained by feeding the nitrate at the 
bottom of the bed. Finely divided fused mag¬ 
nesium (through 100 mesh) was found to per¬ 
form well as the carrier, and steady nitrate 
decomposition was obtained when the nitrate 
feed was fed at the bottom mixed with from 5 
to 20 times its weight of carrier fines from 
the cyclone separator. The data on absorption 
of nitrogen oxides in the gas stream leaving 
the reactor indicated that a negligible fraction 
of these gases was reduced to nitrogen and that 
their recovery as nitric acid should be practical 
by conventional means. 

The barium product of the nitrate decom¬ 
position at 800 C was primarily oxide mixed 
with a few per cent peroxide (mixed with 
magnesia carrier). Conversion of the oxide to 
the peroxide in air or oxygen takes place 
rapidly and completely at about 600 C, and this 
part of the cycle appears to present no serious 
difficulties if the fluid powder technique is em¬ 
ployed with an inert carrier powder. 


25 5 3 Formation of Dilute Hydrogen 
Peroxide from Barium Peroxide 

The use of sulfuric acid in this step is well 
established but is undesirable because of the 
difficulty of recycling barium sulfate. Using 
phosphoric acid at 0 C and a pH below 4, 95 
per cent conversions were obtained at hydro¬ 
gen peroxide concentrations of 2 to 3 per cent. 

Conversion of barium peroxide to hydrogen 
peroxide was also shown to be practical using 
nitric acid, thus directly producing barium 
nitrate which can be reconverted to the perox¬ 
ide. Conversion of the peroxide so produced 
was 82 to 87 per cent at pH of 1 to 3 at 0 C in 
hydrogen peroxide concentrations of 2 to 2.5 per 
cent. Conversion was greater at the lower per¬ 
oxide strengths. A continuous system for car¬ 
rying out the reaction was described. Loss of 



APPLICATION OF FLUIDIZED POWDER TECHNIQUES 


137 


carrier powder (fused magnesia) due to solu¬ 
tion by nitric acid was shown to be unimpor¬ 
tant. The separation of the peroxide from the 
barium phosphate or barium nitrate in solution 
was not studied carefully, but appears to be 
practical. Concentration of 2 to 3 per cent solu¬ 
tions up to any desired strength can now be 
considered as entirely practical, and not ex¬ 
pensive. 

2554 Conclusions Regarding Barium 
Peroxide Process 

The investigation outlined was inadequate as 
a basis for appraising the full potentialities of 
a barium peroxide process utilizing the new 
fluid catalyst techniques. It did establish, how¬ 
ever, that barium nitrate can be decomposed 
completely using a continuous powder system 
with an inert carrier powder, evolving the 
nitrogen in recoverable form, and that the 
oxidation of barium oxide to peroxide can also 


be carried out in a continuous powder bed. The 
development of a cyclic operation appears to 
present no serious obstacles, and it may be 
that this can be based on barium nitrate, with 
recovered nitric acid used to react with the ba¬ 
rium peroxide. Further laboratory work may 
indicate the desirability of using two acids, 
probably phosphoric for the peroxide reaction 
and conversion of the phosphate to nitrate 
prior to barium oxide production. 

The basic principles of a practical cyclic 
process appear to be established. Such a proc¬ 
ess would require only fuel, water, air (or oxy¬ 
gen), and a small fraction of the power re¬ 
quired by the electrolytic processes. The total 
of fuel and power costs is estimated to be less 
than 1 cent per pound of concentrated hydro¬ 
gen peroxide. Based on laboratory rate data, 
the total power and fuel requirements of the 
process are estimated to be 0.5 kilowatt-hour 
and 400,000 Btu, respectively, per pound of 100 
per cent hydrogen peroxide. 



Chapter 26 

IMPROVEMENT OF SHOES 


261 SUBSTITUTE SHOE SOLES 

T he object of this investigation was to 
find satisfactory substitutes for leather 
used as midsoles, and for GRS used as out- 
soles in Army shoes. In December 1943, be¬ 
cause of the critical shortage of leather, it ap¬ 
peared that some substitute materials must be 
developed if the Army requirement for shoes 
was to be obtained. 

Promising materials were secured from 
manufacturers by maintaining a field repre¬ 
sentative to visit them. Results obtained by 
tests were reported to the manufacturer with 
recommendations for improvement. Over 200 
samples were obtained and tested. 


26,11 Laboratory Tests and Approximate 
Standard Values 

Laboratory test methods were studied and 
a set of standard tests developed which in¬ 
cluded stitch-tear strength, tensile strength, 
water absorption, effect of high and low tem¬ 
peratures, abrasion resistance, and flex-pres¬ 
sure resistance. 

Thickness. Measurements were made with 
an Ames dial gauge. Army shoes should have 
a thickness of 8 iron or more for each sole. 

Density. Determined by weighing and dis¬ 
placement of a mercury column. Leather shows 
about 1.02 grams per cubic centimeter. All 
other factors being satisfactory, the lower the 
density, the better; values above 1.3 would be 
excessively high. 

Stitch-Tear Test. Determined according to 
American Leather Chemists Association 
[ALCA] standards, using a Scott testing ma¬ 
chine. Government specifications require a 
minimum strength of 30 pounds dry and 25 
pounds wet. Since thickness is obviously a 
factor in this test, the values calculated in 
pounds per iron should be above 4 pounds dry 
and 3 pounds wet. 


Tensile Strength and Deformation. The 
samples used were die-cut to ALCA standards, 
with a necked section 1/2 in. wide and 4 in. 
long; these were broken on a Scott machine 
and a stress-strain curve drawn automatically. 
A tentative minimum satisfactory value is 
about 1,200 psi. 

Water Absorption. The sample was condi¬ 
tioned for 5 hours at 55 C, cooled, and weighed; 
immersed in water at about 25 C for 24 hours, 
drained, and weighed. The difference was 
water absorbed. The sample was reconditioned 
for 5 hours at 55 C, cooled, and weighed to 
obtain water-soluble materials. Satisfactory 
midsoles and outsoles have a low water ab¬ 
sorption. Leather absorbs about 70 per cent, 
which is not satisfactory, under 10 per cent 
being more nearly ideal. Water-soluble mate¬ 
rial lost should be as low as possible, and not 
over 2 per cent. 

Cold Cracking. Samples were conditioned 
for 24 hours at —20 C and bent 180 degrees 
over a mandril starting with a 3-in. diameter. 
The diameter over which the sample cracks is 
recorded. Any diameter less than IV 2 in. 
should be reasonably satisfactory. 

Abrasion Resistance. Determined on a modi¬ 
fied Taber abrasion machine. Satisfactory 
leather outsoles wear about 0.9 gram per 
1,000 revolutions, and the present GRS Army 
outsole about 0.4 gram per 1,000 revolutions. 

Flex-Pressure Test. A new type machine was 
developed simulating the bending and rolling 
action under pressure undergone by a shoe sole 
in walking. A material not disqualified by ex¬ 
cessive elongation is considered (1) excellent, 
if it completes 100,000 cycles; (2) fair, if it 
completes 50,000 cycles. When a material 
showed exceptional promise, it was given a 
flex-pressure test under a constant stream of 
water. Under such conditions, 50,000 cycles 
was considered excellent. 

High-Temperature Tackiness. Samples sub¬ 
jected to 55 C for 5 hours should show no 
tackiness. 


138 


ADHESIVES 


139 


A complete description of these tests and 
the results obtained on all samples are reported 
in the Final Report. 

26,1,2 Summary of Results 

Extensive abrasion tests on GRS outsoles 
from different manufacturers disclosed wide 
variations between the products from different 
factories; the best was more than twice as 
good as the poorest. It was also found that, 
in general, the wear resistance of the toe por¬ 
tion (where the greatest wear resistance is 
desired) was lower than that of the shank and 
heel portions. These results were discussed 
with the manufacturers resulting in improve¬ 
ment in the quality of the outsoles being fur¬ 
nished to the Army. 

Laboratory examination of the samples 
tested disclosed two substitute midsoling mate¬ 
rials and two substitute outsoles which were 
outstanding. Both of the midsoles are paper- 
base products impregnated with and bonded 
together by plastic compositions. 

One of these products, although laminated, 
showed no signs of delamination under the 
most strenuous test conditions. It showed 
water adsorption somewhat greater than 
leather, which is not to be desired, but with¬ 
stood flexing under pressure while wet much 
better than leather. The abrasion resistance 
was poor, but a midsole is not required to show 
high abrasion resistance. 

The other midsole material was not lami¬ 
nated. Its water absorption was low, about 
10 per cent, and its abrasion resistance of the 
same order as leather. 

The outsole products both consisted of a 
vinyl plastic sheet in which was incorporated 
a fiber base. In one product the fiber base was 
a carpet-weave fabric and in the other it was 
a loose felt. The latter is to be preferred as it 
gives a smoother edge finish to the shoe sole. 
Both these outsoles had all the desirable char¬ 
acteristics for good soles and were particularly 
outstanding in their abrasion resistance, which 
indicated that they should outwear leather six 
or eight to one. 

Civilian wear tests corroborated the labora¬ 
tory findings and several hundred Army shoes 


were built for a test at Camp Lee. As of March 
1946 this test still was in progress. The results 
obtained to date are encouraging. 

On the basis of these facts it is recommended 
that both the midsole and outsole materials 
described be used in Army shoes. 


262 ADHESIVES 

The objects of this phase of the investigation 
were: (1) to obtain adhesives which would 
give a permanent bond between the leather 
midsole and GRS outsole of Army shoes, and 
(2) to obtain an adhesive and method for 
cementing the insole lip of oil-treated insoles. 

When GRS outsoles are sewed to leather 
midsoles, as is done in the present type of 
construction of Army shoes, there is a ten¬ 
dency during wear for a pocket to develop be¬ 
tween the two which allows water and mud to 
accumulate. It was felt that if these two soles 
were cemented together the shoe would be much 
better and show longer life. 

Since the majority of Army shoe failures 
appear to be due to disintegration or mal¬ 
formation of the insoles under wear conditions, 
a method was developed at the University of 
Cincinnati for oil treating insoles which would 
approximately double their life. A manufactur¬ 
ing difficulty arose, however, in the manufac¬ 
ture of these oil-treated insoles into shoes, as it 
proved to be impossible to form the insole lip 
with the adhesives generally used for that pur¬ 
pose. It became necessary, therefore, to devise 
some new method for this manufacturing 
operation. A new adhesive was needed which 
would work on oil-treated leather insoles, and 
it was desirable that it be not critical as to 
drying time, thereby eliminating all elements 
of employee judgment as to when the parts 
were ready to be put through the lip forming 
operation. 

It was obvious, from investigation, that no 
adhesives presently used in the shoe industry 
could be relied upon to accomplish either the 
sole-cementing or the lip-cementing jobs. Other 
industries, therefore, were investigated, such 
as the automotive, airplane, and plastics. A 
number of adhesives entirely foreign to the 




140 


IMPROVEMENT OF SHOES 


shoe industry were discovered, and these were 
tested to evaluate them for the problems at 
hand. 

This involved setting up a standard proce¬ 
dure for evaluation of adhesives in the labora¬ 
tory, as no accepted standards were available 
in the industry. This was done, and is fully 
described in the Final Report. Preparation of 
the sample, application of the adhesive, and 
the test methods were all of importance. 

Over 70 samples of adhesives were tested in 
the laboratory, and the results obtained with 
each are reported. The lip-setting operation 
involves a leather to leather bond under ex¬ 
tremely short pressure dwell, while the midsole 
to outsole problem involves the bonding of 
leather to GRS. Both were tested for all 
samples, and the best adhesive determined. 


26 2 1 Summary of Results 

The results of laboratory work indicated that 
the strongest bonds could be secured by apply¬ 
ing the adhesive, usually in two coats, allowing 
it to dry completely, and then heat activating 
the surfaces just before they are pressed to¬ 
gether. By this method it was possible to avoid 
any critical drying time until the adhesive be¬ 
came “tacky,” as is the case with adhesives now 
in use in the shoe industry. 

It was also found that the best adhesives, 
made by several manufacturers, were all of the 
same general type, containing Buna N as a 
principal ingredient. Solvents are important, 
and some evidence exists that the useful shelf 
life of these adhesives depends largely upon 
the use of proper solvent combinations. 

Adhesive bonds obtainable with the latex- 
type adhesives at present in use in the shoe 
industry have strengths of 10 lb or under per 
in. of width. With the adhesives of the new 
type, heat-activated bonds of 30 lb or over per 


in. of width may always be obtained either for 
leather to leather or leather to GRS. Results as 
high as 92 lb per in. of width were obtained in 
the laboratory tests. The cementing of GRS 
outsoles to leather midsoles by this method and 
using the recommended adhesives is entirely 
possible. In fact, bonds may be obtained which 
make stitching unnecessary. 

Laboratory tests on lip setting resulted in 
the development of a new method for which 
patent application has been made. In this meth¬ 
od the adhesive is applied over the channelled 
insole and allowed to dry. The lip is then set 
in a standard lip-setting machine which has 
been fitted with a jet, causing hot air to im¬ 
pinge upon the adhesive-coated surfaces of the 
lip just before they enter the rollers which 
pinch them together. The speed of the machine 
is such that only the surfaces of the adhesive 
are heated to the activation point, the leather 
itself remaining cold. 

Lips formed by this method proved much 
stronger than those made by the conventional 
method. In addition, there was no difficulty in 
using these adhesives and the hot-air jet meth¬ 
od for lip setting of oil-treated insoles. In 
fact, it was found that the adhesive could be 
applied to the insoles while still wet from the 
oil treatment and then dried. 

A factory test was made at the Army Shoe 
Rebuilding Plant at Hannibal, Missouri, which 
was completely satisfactory. Several hundred 
pairs of insoles were oil treated, the adhesive 
applied, dried, and subsequently lip-set by the 
hot-air jet method. All were satisfactory and 
were built into Army shoes. 

As a result of this work, it was recommended 
that Army shoes be built with the GRS out¬ 
soles cemented to the leather midsoles using 
one of the approved adhesives and heat ac¬ 
tivated. Also, it was recommended that the hot¬ 
air jet method of lip setting be adopted on 
Army shoes. 



Chapter 27 

IMPROVEMENT OF LEATHER 


T his project on the improvement of leather 
investigated synthetic tanning materials, 
mold resistance of leathers, special treatments 
to improve leather, and methods for increasing 
water resistance of Army shoe upper leathers. 


2 7 i DEVELOPMENT OF NEW 

SYNTHETIC TANNING AGENTS 

The objectives of this program were (1) to 
minimize the possibility of a shortage of 
vegetable tannins and (2) to obtain better 
leather through the use of synthetic tannins. 
The physical wear of sole leather was not so 
satisfactory as desired under severe conditions. 
German patents applicable to the problem 
were reviewed, and synthesis and evaluation 
of 60 examples taken from these patents were 
accomplished. The influence of the acidity or 
alkalinity of the system and the weight ratio 
of the two components upon tanning of the 
furfural-resorcinol polymers were also evalu¬ 
ated as a basis for future work. The expense 
involved in the use of these polymers as pure 
tanning agents was prohibitive. It was shown 
that, when in combination with waste liquors 
from the sulfite-cellulose paper industry, a 
product with very desirable properties was ob¬ 
tained. The various sulfite-cellulose products 
which are available were studied in order to 
make possible an intelligent choice of the sul¬ 
fite-cellulose waste to be used. 

Leathers treated with various products were 
evaluated from a variety of standards, and 
from this evaluation a group of formulations 
were selected as worthy of pilot plant study. 
Conditions were established for the preparation 
of these formulations in the pilot plant of the 
Monsanto Chemical Company and arrange¬ 
ments completed for the use of eight of these 
formulas in the experimental tannery of the 
American Oak Leather Co. 

Although the resistance of glyoxal-resorcinol 
tannages to alkaline detannization was in¬ 


teresting, the investigation was not carried 
beyond the laboratory stage. 


272 MOLD RESISTANCE OF LEATHERS 

Whenever leather is used or stored in an 
atmosphere where the humidity is high and the 
temperature is 70 F or higher, mold develop¬ 
ment will occur. All disinfectants adaptable to 
leather were evaluated and the best method of 
application determined. The American Leather 
Chemists Association method was used for 
evaluation and treatment. From a series of 
special reports on this subject, it is found that 
p-nitrophenol was a suitable disinfectant. It 
was approved in limited concentration in 
dubbin by the Surgeon General. The effect was 
enhanced when p-chloro-m-xylenol was used in 
combination. Shirlan (salicylanilide) was 
evaluated and found to merit further work. 
Based on effectiveness, low toxicity, and avail¬ 
ability, p-chlorophenol and tetrachlorophenol 
were recommended. 

In the use of a mold resistant treatment, care 
must be exercised in selecting an agent which 
(1) is effective, (2) is economically and practi¬ 
cally available, (3) has no deleterious influence 
on the leather, and (4) has very low toxicity to 
persons wearing or handling the leather. No 
definite knowledge has been collected on the 
actual damage done by molds and associated 
micro-organisms. Most of the organisms en¬ 
countered, except in shoes, were nonpathogens, 
but the same conditions which permit or cause 
molds to grow are also conducive to the growth 
of disease producing organisms. 


27.3 SPECIAL TREATMENTS TO 
IMPROVE LEATHER 

The following results were obtained in a 
study of special treatments to give leather spe¬ 
cial characteristics or protection. (1) Suitable 


141 



142 


IMPROVEMENT OF LEATHER 


wax impregnations were developed to give 
firmness to leather. (2) Synthetic resins avail¬ 
able and included in this study improved wear, 
but were no better than the oil-grease treat¬ 
ment. (3) Tests showed that there is little cor¬ 
relation between resistance to abrasion and 
actual wear; also resistance to abrasion was 
found not to be capable of correlation with the 
chemical analysis of leather. (4) Rapid dete¬ 
rioration of insole leather, characterized by 
curling, cracking, buckling, and shrinkage, was 
found to be due to the influence of wetting and 
drying and the alkaline nature of perspira¬ 
tion. (5) Because of the shortage of brass, 
aluminum, copper, and other metals, it was 
necessary to use iron in the Army shoe; iron as 
such has a definite deteriorating influence on 
vegetable-tanned leather. (6) Aside from the 
fact that Canadian tanners had better hides to 
tan (they made heavier leather) and no limita¬ 
tion on chrome, their leathers were by analysis 
no better than ours; shoes made of these 
leathers and tested in actual service at Camp 
Lee substantiated this conclusion. (7) The in¬ 
fluence of perspiration on insole leathers, the 
influence of alkaline soil solution and its pene¬ 
tration into flesh out leathers, and the preven¬ 
tion of shrinkage of leather midsoles were also 
studied. 


274 STUDIES TO INCREASE WATER 
RESISTANCE OF ARMY SHOE 
UPPER LEATHER 

This problem was concerned with many 
other factors, such as water absorption, the 
rate of flow through leather, and drying char¬ 
acteristics, as well as shoe construction. 

Numerous special reports were issued in¬ 
cluding: a preliminary study of the influence 
of oils when added to finished leather; a report 
on Canadian leather; a resume of the charac¬ 
teristics of Army shoe upper leather; a dy¬ 
namic water penetration test to determine 
what leather will do in service; area shrinkage 
of grain and flesh out Army leathers; impreg- 
nite (an oil, grease, etc., composition developed 
by the Chemical Warfare Service) as an equal 
to any other compound or material evaluated 
for water resistance; water penetration tests 
of shoes, in which not much difference was 
found between shoes of grain out and of flesh 
out leathers; evaluation of lanolin for water 
resistance; influence of hardness of greases; 
influence of resins and other materials. 

It is believed that only by a knowledge of the 
fundamentals of skin chemistry and tanning 
mechanism can a leather with a maximum 
water resistance be produced. 





Chapter 28 

DELEADING OF GASOLINE 


28i INTRODUCTION 

T he purpose of this investigation was to 
devise a convenient and rapid method for 
deleading Army gasoline. Two methods for ac¬ 
complishing this purpose were developed; they 
are called, respectively, the “fast” and the 
“slow” (overnight) processes. 


281,1 Fast Process 

The first step in the fast process is to treat 
the leaded gasoline with tin tetrachloride. The 
mixture is then treated with a slurry composed 
of ligroin in which triethylamine is dissolved 
and powdered activated charcoal is suspended. 
The triethylamine combines with the lead and 
tin compounds to form flocculent insoluble 
products which are adsorbed on the charcoal. 
The deleaded gasoline is then separated from 
the charcoal and adsorbed material by de¬ 
cantation. 

By use of the fast method, 5 gallons of gaso¬ 
line can be almost completely deleaded within 
40 minutes. The gasoline recovered in deleaded 
form is 95 per cent of the leaded gasoline used. 
If the leaded gasoline contains a low percent¬ 
age of unsaturated hydrocarbons, the gum 
content of the gasoline is not much increased. 
When gasoline containing a high precentage of 
unsaturated hydrocarbons is used, the increase 
in gum content is greater, but still not enough 
to be harmful. 


28,1,2 Slow Process 

The gasoline is treated with triethylamine 
perhydrobromide (C 2 H 5 ) 3 NHBr-2HBr in the 
slow process. A flocculent precipitate is 
formed. Powdered activated charcoal which 
adsorbs this precipitate is added. Then the 
deleaded gasoline is separated from the char¬ 
coal and adsorbed material by decantation. The 


reason for the slowness of the process is that, 
after the addition of the perhydrobromide, the 
gasoline must be allowed to stand in contact 
with the charcoal for at least 10 hours in order 
to secure satisfactory removal of the lead. 


282 RESULTS 

After the “fast” process had been developed, 
kits designed for field use were planned in 
cooperation with the Quartermaster Corps. Re¬ 
sults of laboratory experiments with this meth¬ 
od, and field tests with the kits have established 
the following facts: 

1. The deleaded gasoline contains: 

a. An amount of lead equivalent to 0.05 
to 0.20 ml of tetraethyl lead per gallon. 

b. Less than 20 mg of gum per 100 ml of 
relatively saturated gasolines, but be¬ 
tween 100 and 200 mg of gum per 100 
ml of highly unsaturated gasolines. 

c. No compounds of tin. 

d. No coloring matter. (The deleaded 
gasoline may thus be easily distin¬ 
guished from the original material.) 

e. No substance which corrodes copper or 
steel. 

2 . When the deleaded gasoline is withdrawn 
from a 5-gallon “blitz” can, there is left in the 
can 1,000 to 1,500 ml of gasoline and charcoal 
sludge. Thus 90 to 95 per cent of the gasoline 
is recovered in deleaded form. After the sludge 
is dumped, the can is ready for use in delead¬ 
ing another lot of gasoline. 

3. A liter or two of deleaded gasoline is ob¬ 
tained at the end of 20 to 30 minutes. The 
entire 5 gallons of deleaded gasoline (minus 
the 1,000 to 1,500 ml left behind with charcoal 
sludge) is obtained in 30 to 45 minutes. Within 
this period, only about 10 minutes of actual 
labor is required. The remainder of the time is 
consumed in draining the can, etc. 


143 


144 


DELEADING OF GASOLINE 


283 CONCLUSIONS 

With gasoline containing only small amounts 
of unsaturated hydrocarbons, the slow process 
gives results which are equivalent to those ob¬ 
tained by the use of the fast process. When 


gasoline containing larger amounts of un¬ 
saturated hydrocarbons is used, the slow proc¬ 
ess fails to remove considerable portions of the 
lead and increases the gum content. For this 
reason, this process is not recommended for 
use with gasoline of this type. 







Chapter 29 

EVALUATION PROCEDURES FOR WATER-REPELLENCY TREATMENTS 


SUMMARY 

T he importance of water-repellent clothing 
has been recognized for some time. Since 
no methods were available for quickly predict¬ 
ing the service that would be obtained from 
water-repellent clothing under the severe con¬ 
ditions of military use, an investigation of test 
procedures was necessary. The purpose of the 
investigation was to evaluate the procedures 
for measuring water-repellency treatments and 
to correlate laboratory studies with Army field 
tests. The scope of the investigation included 
new test procedures, evaluation of various 
water-repellent finishes, the durability of water- 
repellent finishes to wear and laundering, the 
effect of detergents and sea water on water 
repellency, and the influence of air permeabil¬ 
ity, of the nature of the fabric, and of under¬ 
layers on resistance to penetration by rain. 

292 EVALUATION OF TEST 

PROCEDURES 

29.2.1 The Drop-Penetration Test 

The apparatus consisted of a drop former, 
a support for the fabric to be tested, and an 
electrical signaling device to indicate failure of 
the fabric. The drops issued at a rate of one 
per second from each of 31 capillaries and fell 
5 ft 8 in. through a tube (to protect them from 
air currents) before striking the sample. The 
drops had a volume of 0.075 ml. The sample 
was held under slight tension over a backing 
of 12 layers of absorbent gauze. The latter was 
supported by a transparent plastic plate held 
at a 45° angle. When water passed through 
the sample, the gauze was moistened, and an 
electric circuit was completed between the wires 
of a grid embedded in the surface of the plastic 
plate. When the circuit was closed, a buzzer 
sounded to indicate the end point. 

In tests with natural rainfall, samples of 
the water-repellent fabrics, mounted as in the 


drop-penetration test, were exposed and the 
penetration of water was observed by the use 
of a water-soluble dye in the backing. The re¬ 
sults of the drop-penetration test correlated 
satisfactorily with the results of tests with 
natural rainfall. 

The other methods of evaluating water re¬ 
pellency do not in every case correlate with the 
results of drop-penetration tests or with natural 
rainfall. This result was illustrated by tests 
with water-repellent 5-oz poplin and 13-oz 
jungle cloth. Even where there existed corre¬ 
sponding variations in the results of other 
tests, the drop-penetration test was a more sen¬ 
sitive measure of differences between fabrics; 
e.g., the samples containing 1.2, 2.5, and 3.5 per 
cent, respectively, of a nondurable finish dif¬ 
fered only slightly in their air permeabilities, 
spray ratings, per cent absorption, and hydro¬ 
static pressure values, whereas they showed 
rather large differences in their drop-penetra¬ 
tion times. 

In addition to factors inherent in fabrics, 
variables inherent in the backing influence the 
resistance to penetration by falling drops. 
When the water-repellent samples were backed 
with a plate of transparent plastic, it was noted 
that the first drop to strike the fabric invari¬ 
ably penetrated, owing apparently to the almost 
complete lack of cushioning effect, so that most 
of the energy of the drop was available for 
penetrating the fabric. With a sweat shirt 
backing, the initial penetration was observed in 
practically the same time as with no backing, 
while longer times were required when gauze 
compress or blotting paper was used. Although 
they contained sufficient viscose so that they 
absorbed water rapidly, the two serges tested 
as backings caused a marked increase in the 
time required for initial penetration. Experi¬ 
ments showed also that, for the absorptive ma¬ 
terials used as backings, the time required for 
initial penetration was at least in part related 
to the contact made between the water-repel¬ 
lent fabric and the backing. 


145 



146 


FACTORS AFFECTING VALUE OF WATER-REPELLENT FABRICS 


Moisture in the backing caused an important 
reduction in the resistance to rainfall of a 
water-repellent fabric, but the water repellency 
of the thoroughly wetted fabric was not re¬ 
stored when it was tested over a dry backing. 

The observations on the influence of the 
backing on the results of drop-penetration tests 
suggested the use of two layers of water-repel¬ 
lent fabric. 

In cases where increased severity of the test 
was required, a modified drop-penetration test 
(gauze backing omitted) or the du Pont Rain 
Test was used. In this test the fabric is sub¬ 
jected to heavy streams of water for 5 minutes 
at heads of 2, 4, 6, and 8 ft, the amount-of 
penetration being measured at each head, and 
the fabric is rated according to the sum of the 
weights of water passing through at these four 
heads. 

29 2 2 Other Test Methods 

Surface tests included spray rating, “pearl” 
tests, and contact angle measurements. Ab¬ 
sorption tests were useful in indicating how 
much water was taken up by a finished product. 
There was no direct relation of these tests to 
the protection against rainfall. Water-perme¬ 
ability tests were especially useful for testing 
fabrics designed for immersion suits, water 
buckets, etc. Of all the conventional tests, 
hydrostatic pressure tests appeared to correlate 
most closely with rainfall, particularly when a 
series of fabrics of the same weight and con¬ 
struction were compared. A high hydrostatic 
pressure value almost invariably meant good 
resistance to rainfall, but the converse was not 
always true. 

293 DURABILITY OF WATER- 

REPELLENT FINISHES 

Poplin was treated with nine durable type 
finishes and subjected to wear under compar¬ 
able conditions, i.e., all factors pertaining to 
fabric and garment construction were made as 
constant as possible. From tests on these treat¬ 
ed pieces, it was concluded that the relative 
durability of finishes applied to cotton goods, 
which will be subjected during their service 


life to wear and laundering only, can be quickly 
determined by tests before and after a number 
of launderings. 

29 4 REDUCTION OF WATER 

REPELLENCY RESULTING FROM 
LAUNDERING 

Experiments were performed to determine 
the effect of laundering with various deter¬ 
gents : a high titer soap, Nacconol NRD, 
Igepon T, du Pont MP-189, and Neutronyx 
No. 33. In the reports which cover this work 
several tables of data are presented, and the 
results indicated that the small amount of de¬ 
tergent remaining in a fabric after laundering 
should not seriously affect its water repellency. 

29 5 REDUCTION OF WATER 

REPELLENCY RESULTING FROM 
IMMERSION IN SEA WATER 

Samples of poplin treated with nine durable 
water-repellent finishes were agitated in the 
surf of the Atlantic Ocean for 1 hour, at the 
end of which the samples were thoroughly 
wetted. The fabrics were allowed to dry on 
the sand without wringing, and then were sub¬ 
jected to the spray, hydrostatic pressure, drop- 
penetration, and air-permeability tests. They 
were retested after two 10-minute rinses in 
conditioned fresh water at 100 F. The drop- 
penetration times of all unrinsed samples were 
seriously reduced as compared with the un¬ 
treated controls. The rinsed samples were all 
higher in air permeability than the respective 
unrinsed materials, suggesting that the salts 
deposited in the unrinsed fabrics were in part 
responsible for their reduced air permeabilities. 
The results suggest that, for at least three of 
the finishes examined, the repellency of fabrics 
immersed in sea water can for the most part 
be restored by rinsing with fresh water. 

296 FACTORS THAT AFFECT THE 
VALUE OF WATER-REPELLENT FABRICS 

The value of water-repellent fabrics depend¬ 
ed in large measure on fabric construction as 
well as the nature of the finish. The water- 



CONCLUSIONS 


147 


permeability test, like the hydrostatic pressure 
test, measured a quantity that is affected by 
both the fabric construction and the finish. The 
air permeability test measured only the tight¬ 
ness of weave of the fabric, and is not affected 
by'the finish. Differences introduced by varia¬ 
tion in twist factor are overshadowed by small 
differences in construction and possibly in 
finish. 

29 7 THE USE OF TWO LAYERS OF 
WATER-REPELLENT FABRICS 

An important improvement in the protection 
afforded by water-repellent garments can be 
obtained by the use of double-layer construc¬ 
tion. The resistance of penetration shown by 
two layers of water-repellent fabric was many 
times as great as that of a single layer. A 
double-layered garment consisting of a tightly 
woven water-repellent outer layer and a thick, 
resilient, water-repellent inner layer would 
represent a very desirable construction. On the 
other hand, the use of absorbent linings in 
water-repellent garments was contra-indicated. 

298 CONCLUSIONS 

The results of this investigation indicated 
the following conclusions. 


1. The relative protection afforded in actual 
rainfall by a series of water-repellent fabrics 
can be estimated by means of the drop-penetra¬ 
tion test. 

2. For a series of fabrics of similar weight 
and construction, the results of the hydrostatic 
pressure test correlate closely with results of 
the drop-penetration test. 

3. The relative durability of water-repellent 
finishes to field wear can be estimated by 
measuring their repellencies before and after 
suitable laundering procedures. 

4. The deterioration of water-repellent fin¬ 
ishes as a result of laundering is caused in 
large measure by the mechanical action they 
sustain in the wet state, rather than from 
specific effects of the detergent used. 

5. Resistance to penetration by rainfall is 
affected to a marked degree by fabric construc¬ 
tion, especially in the range of the tighter 
fabrics now used for military purposes. Even 
a slight improvement in tightness of weave 
may result in a very large improvement in re¬ 
sistance to rainfall. 

6 . The use of double-layer constructions, 
especially with a resilient, water-repellent un¬ 
der layer, results in a very large improvement 
in the efficiency of water-repellent garments. 




Chapter 30 

INSECTS AND OTHER ANIMALS OF INTEREST 


301 SUMMARY 

T he final report is an exhaustive com¬ 
pendium of the insects reported to damage 
articles of the character represented by 
Quartermaster items. The data are derived 
from the consideration of material in thou¬ 
sands of papers, examined by the author either 
in the original or in abstract. This report is 
intended to serve as a basis for the selection, 
by the proper authorities, of a series of control 
measures and for the establishment of a control 
organization, which should lead as far as pos¬ 
sible to the elimination of damage from insect 
attack. 


30.2 INTRODUCTION 

It was necessary to consider the substances 
of which military equipment and supplies are 
composed and to consider the various methods 
used in packing and storing equipment. In 
general, everything of animal and plant origin 
(wood, fiber, fur, adhesive, or food) was con¬ 
sidered in the form in which it was likely to be 
used in military operations. Also included is a 
considerable number of insects found in build¬ 
ings, although no definite information on their 
food is available. 


30 2 1 Kinds of Damage Done by Insects 

Practically all the insects considered do their 
damage by actually biting off and chewing the 
material; hence, whether or not they digest any 
of the material, they still effectively remove 
it. A few insects, notably roaches, spoil food 
by merely passing over it, since they leave be¬ 
hind substances of disagreeable odor. The main 
classes of organisms which do appreciable dam¬ 
age are mammals, the insects and arachnids, 
and the fungi. 


30,2,2 Relations of the Animals to the 
Material Damaged 

Insects may be classified as permanent pests 
(material infested as long as it has adequate 
food or shelter value), bark pests (beetles in¬ 
fest wood continuously as long as it is covered 
by bark), one-generation pests (material must 
be in some special state of curing in order to 
be infested; insects go through life cycle and 
then seek new material), secondary pests 
(these follow damage by primary insects or 
are attracted by some microorganism which 
is the source of primary damage), temporary 
pests (carpenter bees and wasps), accidental 
pests (attack inedible material or edible ma¬ 
terial out of the ordinary range of an insect’s 
food, e.g., metal), and predators and parasites 
(do not actually damage the material on their 
own account). 

Basic biological information on insects covers 
their structure, food habits and food getting, 
reproduction and development, requirements 
for existence, distribution, and dissemination. 


30.3 MATERIALS ATTACKED AND NOTES 
ON THE DIAGNOSIS OF DAMAGE 

Under each of the 52 groups of materials 
those organisms are indicated which are most 
frequently found as pests and, where possible, 
the type of damage for which they are re¬ 
sponsible; the distribution and expected inten¬ 
sity of damage; the significance of infestations 
of the particular group of materials in relation 
to infestation of other groups of materials. 
Also shown is the relation of the infestation 
to the use of the infested material, where use 
can be made of it to give clues to personnel in 
the field to determine causes of damage. In¬ 
cluded in this discussion are foods and closely 
related materials, equipment and supplies, and 
their raw materials, materials of construction, 
metals, houses and storehouses. 


148 


SUMMARY OF CONTROL METHODS AND SUBSTANCES 


149 


30.3.1 Systematic Discussion of the 
Animals 

The organisms considered are arranged in 
what a biologist considers systematic order. 
This discussion covers the following insects: 
Thysanura, Orthoptera, Dermaptera, Isoptera, 
Embioptera, Psocoptera, Ephemeroptera, Tri- 
choptera, Lepidoptera, Coleoptera, Hymanop- 
tera, and Diptera; Mites, Teredos, and Mam¬ 
mals (rodents and carnivores). 

30 4 SUMMARY OF CONTROL METHODS 
AND SUBSTANCES 

Insect infestation may be prevented by sepa¬ 
rating the insects from the material to be pro¬ 
tected by an impassable barrier (e.g., by using 
a copper shield between concrete foundation 
and the wood of a building or by using insect- 
tight glass or metal containers for food) ; 
poisoning the material (impregnation of wood 
with creosote) ; substituting immune materials 
(e.g., concrete instead of wooden posts under 
buildings) ; and environmental control (cold 
storage of furs). After insects have reached 
and started to multiply in the material, they 
may be killed by physical methods (heat, pref¬ 
erably at least 140 F) ; poison (baits, sprays, 
solid contact poisons, and fumigation) ; and 
biological methods, utilizing certain predacious 
or parasitic organisms which attack the species 
of insect. A brief review is presented of some 
of the methods recommended for each group 
of animals. 

30 41 Geographical Summary 

A brief description is given of each of the 
following natural geographic regions into 
which biologists have divided the world, and in 
which it is supposed that a large group of Army 
personnel will eventually be operating: North 
America (The Northeast, Southeast, West 
Coast, and Alaska), Central America, West 
Indies, South America (Northern Coastal Re¬ 
gion), Europe and North Africa, Africa (Eri¬ 
trea, West Africa), Asia (Western Asia, India, 
Burma and Malaya, Southeastern and Eastern 
Asia), Dutch East Indies (Dutch Islands, west 
of Wallace’s line, The Philippines, islands from 
Wallace’s line to western New Guinea), Aus¬ 


tralasia (New Guinea, Tropical Australia, and 
Temperate Australia), the Pacific Islands (Mi¬ 
cronesia, islands east of New Guinea, New 
Caledonia, New Zealand, etc., the Fijis, Cen¬ 
tral Pacific Islands, Hawaii, and the Gala¬ 
pagos). 

30 ' 42 Conclusions 

The Appendix to the Final Report lists ap¬ 
proximately 1,050 species of insects and mites 
which either are known to damage materials 
of interest to the Quartermaster Corps, or very 
similar substances, or have been found in 
buildings and are related to destructive insects. 
It is noted that the most important natural 
groups of insects are beetles, termites, and 
moths; however, in the case of fresh meat the 
flies play the major role and in the case of 
buildings ants are most dangerous. 

In cases where infestation begins before food 
was packaged, the incidence of such damage 
can be diminished by careful selection of stock, 
cleanliness, control to prevent building up of 
insect population, and final heating of package 
after sealing to kill any insects which may still 
be present. As yet no universal package has 
been developed which will be proof against 
invasion by all insects. 

Equipment and supplies can be protected, 
while in storage, by using closed containers, 
p-dichlorobenzene, cold, and buildings immune 
and unattractive to insects. When the equip¬ 
ment is being used, its protection will have to 
depend on insectproofing or the use of materials 
which are themselves inedible; unfortunately, 
relatively few of the possible materials such 
as synthetic fibers or plastic substitutes for 
leather have been tested to determine the ef¬ 
fect of insects upon them. 

Buildings and materials used can be protected 
against insect attack by structural, chemical, 
or environmental means. The protective effect 
of metals resides almost entirely in the physi¬ 
cal character of the particular metal, i.e., if 
the metal is soft enough it will be penetrated 
by insects. 

The criteria for choice of a poison involves 
not only the efficacy of the poison in question 
in connection with a given method of applica- 



150 


INSECTS AND OTHER ANIMALS OF INTEREST 


tion to the pest, but also the disturbance of 
use of the building which is involved, and the 
toxicity to man. 

Practically all insects and arachnids can be 
killed by heating at 160 F for 20 minutes; 
storage of materials at a temperature under 
50 F will normally prevent any increase in the 
number of insects present. According to the 
few references available relating to the mini¬ 
mum moisture required in food to be packaged, 
the range is usually 6 to 10 per cent. Mammals 
must be attacked by specially prepared and 
placed baits, or with traps in case of rodents. 

3043 Recommendations 

The following recommendations are made. 
(1) Obtain and disseminate information on 


which control measures may be based. (2) 
Issue regulations and manuals covering at least 
the basic items in the supervision and per¬ 
formance of pest control. (3) Develop means 
of obtaining the most effective actual opera¬ 
tions against insects and rodents. (4) Write 
specifications aimed toward obtaining certain 
raw and processed foods, as nearly as possible 
free of infestation when delivered to the Quar¬ 
termaster Corps. (5) Develop means of test¬ 
ing, both in the laboratory and in the field, the 
efficiency of such substances and methods as 
may be proposed for pest control, as well as 
determine the possibilities of insect attack on 
newly proposed or invented materials, such as 
synthetics. As a corollary, there are included 
substances applied as preservatives against 
other conditions, such as mildew and rot. 



Chapter 31 

TROOP FEEDING PROGRAMS 


ail SUMMARY 

A COMPREHENSIVE INVESTIGATION of troop 
feeding in the United States Army from 
the Revolutionary War (1775) to the beginning 
of World War II (1940) is presented. The proj¬ 
ect, undertaken to provide historical perspec¬ 
tive for the evaluation of current subsistence 
problems, is discussed in the following sec¬ 
tions : I. Establishment of the Ration for 
Troops and Legislation Pertaining Thereto, 
1775-1789; II. Legislative Changes Affecting 
the Ration, 1789-1818; III. Subsistence and 
Rationing under the Commissariat, 1818-1861; 
Supplement: Army Regulations and Revised 
Statutes; IV. The Ration in the Period of 1861- 
1912, including the Civil and Spanish Wars; 
Supplement: Army Regulations and Special 
Statutes; Appendix: Quotations on Use of 
Ration by the Soldier; V. Subsistence and 
Rationing under the Quartermaster Corps; 
Appendix: The Work of the Food Division, 
Sanitary Corps. 


31 2 HISTORY OF TROOP FEEDING IN 
THE AMERICAN ARMY 

A general review of the methods of provid¬ 
ing subsistence for troops of the American 
armies either in active warfare or in periods 
of inactivity is combined with a resume of the 
more important legislation necessary to author¬ 
ize and fix procedures and standardize rations. 

Since the food supply of the Army and Navy 
must be drawn from, and be closely associated 
with, the national food supply and its produc¬ 
tion, and must be transported, it is apposite to 
call attention to the dependence on agriculture 
and facilities for transportation. Our enormous 
expansion in broad agriculture and animal 
husbandry has supplied the basic foods needed 
for the diet of the fighting men. This diet has 
been greatly broadened in later decades 
through the specialized developments in food 


preservation and conservation which have 
come into practical use during the past hun¬ 
dred years and which have all contributed 
greatly to the solution of the problems of Army 
subsistence. Changes in modes of transporta¬ 
tion from the oxcarts of the Revolutionary 
days through the period of mule- and horse- 
drawn carts to railroad and motor truck have 
done much to solve distribution problems. The 
development of canning as applied to meats, 
vegetables, fruit, and condensed or evaporated 
milk; the wholesale partial drying of fruits and 
vegetables; refrigeration of meats and other 
products; and dehydration of milk, eggs, 
meats, etc., have been of vast significance in 
improving the available diet for men in service 
and in making possible the economical trans¬ 
portation of foods. Thus it can be seen that 
the matter of troop feeding in modern warfare 
is closely associated with these great commer¬ 
cial and industrial developments. 

The general survey of the history of the 
ration and of troop feeding is presented as a 
continuous account of the procedures which 
have been followed in the American Army from 
its early days. The developments and evolu¬ 
tionary changes which have been made are 
recorded. Such an account includes a record 
of early usages, the difficulties encountered in 
methods of procuring food and its administra¬ 
tion and distribution, and the legislation nec¬ 
essary to authorize and accomplish changes 
which have been found desirable or necessary. 

Despite tremendous fluctuations in the 
demand for food for fighting armies, there has 
been a certain similarity in the character of 
the basic foods during the entire period, the 
staples of bread and meat in some form con¬ 
stituting the two principal ingredients of the 
army ration. The last quarter century has 
seen modifications providing a better balanced, 
more pleasing, and much broader dietary, 
partly as a result of experience, but to a 
greater extent because of the improved knowl¬ 
edge of nutrition and of the needs of the body 


151 


152 


TROOP FEEDING PROGRAMS 


under various types of stress. This scientific 
progress has made it possible and practicable 
to fortify and improve the basic components 
of the ration, but has not changed their 
amounts to an extensive degree, except to make 
them more compact. 

The many changes in the size and character 
of the Army during the past one hundred and 
fifty years have made the problems of supply 
extremely variable, ranging from the feeding 
of a few hundred men in posts or garrisons 
in the early nineteenth century to the present 
tremendous demands for food for millions of 
men, not only in continental United States, but 
in various other widely scattered parts of the 


world, many of which are remote and without 
normal transportation services. The difficulties 
in maintaining a regular standardized and con¬ 
sistent method of troop feeding have therefore 
been varied and often acute. As food must take 
first place as a munition of war, this situation, 
enormous in its magnitude, has been met in a 
remarkable manner. 

This review covers not only the nature and 
quantity of the rations supplied, but also the 
part which the soldier has had to play in re¬ 
ceiving and dealing with them. 

A selected bibliography containing approxi¬ 
mately 175 references chronologically arranged 
is given. 



Chapter 32 


WESTERN HEMISPHERE BAMBOO AS A SUBSTITUTE 
FOR ORIENTAL BAMBOO 


32.1 SUMMARY 

I N order to locate, in the Western Hemi¬ 
sphere, suitable species and supplies of 
bamboo meeting the requirements for military 
ski poles, to be used as a necessary alterna¬ 
tive for oriental bamboo now being used, the 
supply of which has been cut off, a project 
was originated in the Office of the Quarter¬ 
master General. The fabrication of experi¬ 
mental ski pole shafts from various bamboo 
samples (collected from southern United 
States, Mexico, Honduras, Canal Zone, Repub¬ 
lic of Panama, Colombia, Venezuela, Brazil, 
Puerto Rico) was undertaken by several manu¬ 
facturers. 

In spite of the fact that it was excelled in 
strength by several of the other species tested, 
Tonkin cane remains the ideal material for ski 
pole shafts. 

322 FABRICATION OF BAMBOO SKI 
POLE SHAFTS 

The principal steps in the making of docu¬ 
mented bamboo ski pole shafts for perform¬ 
ance tests are as follows: selecting the ma¬ 
terial, documenting and marking, shipping, 
seasoning, sawing culms to length, flaming the 
culms, sanding the nodes, preparing labels for 
the transfer of the identification symbol from 
the culm to the prepared strips, stripping the 
culms, milling the strips, assembling the strips, 
mismatching the nodes, cementing the strips 
with a specially prepared animal glue or a 
Bakelite compound, wrapping and straighten¬ 
ing the shaft, curing the cement, impregnating 
(some of the shafts cemented with Bakelite 
compound were also impregnated with another 
Bakelite compound), and preparing the shafts 
for performance tests. 


32.3 PERFORMANCE TESTS 

These experimental ski pole shafts were sub¬ 
jected to the following tests: 

The “deflection” test is described in OQMG 
specification No. 60, Poles, Ski, except that 
the weight required to deflect the shaft 1 in. 
in from straight when applied in the center of 
a 36-in. span, was calculated from a pilot read¬ 
ing based on the actual deflection caused by a 
10-lb weight applied in the specified manner. 
This test was revised in order to prevent pos¬ 
sible permanent deflection, caused by the full 
weight required, which would interfere with 
subsequent tests. 

The “column load” test was conducted in 
accordance with OQMG specification No. 6C, 
except that the maximum compressive load 
sustained by the shaft acting as a column was 
determined. The test was performed on a 
Southwark hydraulic universal testing ma¬ 
chine of 60,000-lb capacity. 

The transverse span-breaking test was con¬ 
ducted according to the specification No. 6C, 
except that the 8-in. span began 5 in. from 
the small end of the shaft. This test was per¬ 
formed on the hand-driven screw type Amsler 
testing machine with pendulum weighing sys¬ 
tem. 

The cantilever test was conducted in ac¬ 
cordance with the specification, except that the 
small end of the shaft was gripped for a dis¬ 
tance of 5 in., and the maximum load was 
recorded at the breaking point. 


324 CONCLUSIONS 

While the number of shafts tested is too 
small to serve as a basis for final conclusions 
on many points, the following statements are 
the result of a conscientious effort to draw 
from the total experience represented by this 
project those trends of evidence which seem 


153 


154 


WESTERN HEMISPHERE BAMBOO 


to be most plain and most significant. Although 
we have not yet found in the Western Hemi¬ 
sphere a bamboo equal to Tonkin cane (Arun- 
dinaria amabUis, commercial Chinese origin, 
taken as the standard of comparison) in all 
respects, we do have available, in quantities 
sufficient to meet the requirements envisaged 
at the time when the project was established, 
bamboos suitable for the manufacture of ski 
pole shafts, well above the Army standard 
minimum performance requirements. 

Bambusa tulda excelled Tonkin cane in aver¬ 
age performance in all prescribed tests. Bam¬ 
busa tuldoides and B. longispiculata excelled 
Tonkin in average performance in two of the 
prescribed tests and were both well above the 
prescribed minima in the other two tests. 
They are not, however, equivalent to Tonkin 
in workability or in the type of fracture de¬ 
veloped on breaking. 

Should the available stocks of Tonkin cane 
prove inadequate, it was recommended that 
a portion of the limited supply of B. tulda and 
B. longispiculata available in Puerto Rico be 
used to make shafts during the interval while 
the machinery was assembled for the exploita¬ 
tion of other species, material for which would 
have to be brought from more distant places. 
Although the culms of B. tuldoides are some¬ 
what difficult to process because of curvatures 
which occur naturally, this species, as it occurs 
in all the States of Rio and Sao Paulo, Brazil, 
probably is, all factors considered, the best 
among the species tested for large-scale ex¬ 
ploitation. 

The three species native to the Western 
Hemisphere ( Guadua amplexifolia, G. angusti- 
folia, and G. superba) which were tested gave 
average performances which were above mini¬ 
mum requirements in all but Test 3. G. su¬ 
perba, with the best average performance of 
the three, is also outstanding in its workability 
and in its low content of superfluous wood. It 
cannot, however, be recommended for exploita¬ 
tion until opportunity is afforded to investigate 
its availability and its accessibility in the areas 
where it occurs naturally. This species is not 
known to be cultivated on a commercial scale. 

G. angustifolia , as it occurs in the valley 
of the Cauca River, Colombia, is a possible 


candidate for exploitation, if the minimum re¬ 
quirements under Test 3 are lowered slightly. 
It is advisable to discard the lower 6 ft or so 
of culms of these species when selecting ma¬ 
terial for ski pole shafts, because of the ex¬ 
treme shortness of the internodes in this por¬ 
tion. 

Of the species cultivated in the United 
States, both Phyllostackys nigra var. henonis 
and Ph. sulphurea var. viridis showed average 
performances well above the minimum require¬ 
ments. Unfortunately, Ph. bambusoides, the 
only one of the three species of the genus 
tested that is available in any quantity, fell 
slightly below the minimum requirements for 
average performance. Also, unimpregnated 
shafts made from the latter species “take a 
set” regularly when subjected to moderate but 
firm lateral stress. In general, the workability 
of these species was considered to approach 
most nearly that of Tonkin cane of any of the 
bamboos tested under this project. 

A more complete understanding of the tech¬ 
nical peculiarities of the bamboos tested should 
make possible improved techniques with result¬ 
ing improvements in performance records. For 
instance, allowing a longer period for the cur¬ 
ing of the culms under natural atmospheric 
conditions or a controlled artificial equivalent, 
before initiating the more severe kiln drying, 
should reduce the incidence of tensions and 
fractures such as are developed as an apparent 
result of the prematurely accelerated drying 
treatment. At least in some instances, the flame 
treatment of the culms (based on a treatment 
accepted as standard for Tonkin cane in com¬ 
mercial practice) resulted in definite damage 
to, and weakening of, the tissues of several of 
the lots of shafts tested. It was recommended 
that heat treatments for Western Hemisphere 
bamboos should not exceed 250 F. It is prob¬ 
able that further experimentation would reveal 
an optimum range for the heat treatment, or 
flaming, of the culms for each species. 

It is believed to be possible, by giving special 
attention to technical peculiarities and require¬ 
ments, to make from selected material of any 
one of the bamboos tested, with the possible ex¬ 
ception of Arundinaria longifolia and Guadua 
amplexifolia, ski pole shafts whose perform- 



CONCLUSIONS 


155 


ance would equal, or nearly equal, the mini¬ 
mum requirements of OQMG tentative specifi¬ 
cation No. 6C. 

The greatest number of failures to meet these 
requirements occurred under Test 3. This re¬ 
quirement probably could be lowered slightly 
without revealing any serious deficiency in the 
quality and “performance in service” of the ski 
pole shafts. 

Although Test 4, as defined in the specifica¬ 
tion, may have been unsatisfactory, it is be¬ 
lieved that the modified execution of this test, 
as conducted in connection with this project, 
proved to be a limitation, rather than an ad¬ 


vantage. An additional variable was intro¬ 
duced (each of the relatively small lots of 
shafts had to be divided in order that one-half 
could be broken in one of the two ways speci¬ 
fied in Tests 3 and 4, respectively). Also the 
important test for “taking a set” was elimi¬ 
nated. With one or two exceptions, the ex¬ 
pected correlation between age of culm and 
performance of shafts made therefrom was 
not demonstrated by the results of the tests. 
This may be due partly to the relatively small 
number of specimens tested and partly to un¬ 
controlled variables. 




Chapter 33 

SOLID FUEL FOR HEATING COMBAT RATIONS 


331 SUMMARY 

A survey is given of materials investigated 
for use in a solid fuel for heating combat 
rations. Seven types of fuel units were specifi¬ 
cally studied, from which a unit composed of 
trioxane as the fuel ingredient, magnesium 
stearate as the supporting agent, and carbon 
black as the pigment, was recommended as the 
most satisfactory. An alternate fuel of Carbo- 
wax 4000 was described. The physical proper¬ 
ties, burning characteristics, and methods of 
formulating and testing were summarized. Rec¬ 
ommendations for the manufacture of the sub¬ 
mitted fuels were given. A change in the size 
of the trioxane unit was recommended as a re¬ 
sult of field use of solid fuels. Data on the evo¬ 
lution of carbon monoxide from the burning 
fuels were presented to disprove the initial 
findings of the Army toxicity tests. 


3 3.2 PURPOSE OF INVESTIGATION 

The purpose of this investigation was a study 
of compositions suitable for the manufacture 
of individual fuel units for heating of combat 
rations. The characteristics which such a fuel 
should possess were given as follows: 

1. High heat of combustion. 

2. A combustion rate favorable for efficient 
heating of from 16 to 20 oz of water from 33 
to 133 F in from 8 to 10 minutes. 

3. Freedom from any volatile toxic product 
of combustion when the fuel is burned freely, 
or with reduced air supply, or with the flame 
in contact with a cold metal surface, or when 
extinguished by smothering or blowing. 

4. Freedom from high initial toxicity; i.e., 
if the fuel should be eaten by mistake. 

5. Free flame of minimum luminosity. 

6. Easy ignition at normal or low tempera¬ 
tures by means of one match. 

7. Clean burning; i.e., without material dep¬ 
osition of soot or gummy deposits on utensils. 


8. Good resistance to wind. 

9. Freedom from hygroscopicity and prefer¬ 
ably insolubility in water. 

10. Freedom from objectionable odors which 
would contaminate food packed in the same 
container, and freedom from objectionable 
odors during burning. 

11. A high melting point preferably about 
140 F. 

It was further stated that the fuel should be 
a compact, preferably rectangular, tablet which 
can be packed directly with the ration package. 

33 3 RECOMMENDED FUELS 

Two fuels were recommended for trial, 
namely, trioxane and Carbowax 4000. The first 
of these was represented as most closely ful¬ 
filling the requirements while the second was 
submitted as an alternate made from a com¬ 
mercially available material which approached, 
but did not fulfill, all specifications. Following 
is a discussion of the manufacture of each of 
these two fuel units. 


33.3.1 Trioxane, Composition, Weight 
and Size of Fuel Unit 

The following summary gives the preferred 
fuel compositions. Only formula No. 1 has been 
used so far to prepare samples and is slightly 
preferred over No. 2. However, No. 2 is some¬ 
what less expensive because of the lower price 
and lesser amount required of calcium stearate. 
Variations of 1 per cent are allowed in these 
formulations. 

Per Cent By Weight 



No. 1 

No. 2 

Trioxane 

97 

98 

Magnesium stearate 

2.8 


Calcium stearate 


1.8 

Carbon black 

0.2 

0.2 


A 30-gram (0.066-lb) fuel unit has sufficient 
heating capacity (457 btu) to raise the tem¬ 
perature of 1 pint of water 100 F. 


156 


CONCLUSIONS 


157 


33,32 Carbowax 4000 

The per cent by weight composition of the 
Carbowax 4000 fuel unit was calculated to be 

89.8 Carbowax 4000 
3.2 Ethyl silicate 
7.0 Igniter D 

However, the composition is better expressed 
as follows: 

100 parts by weight Carbowax 4000 
5 parts by weight Ethyl silicate solution S-1053 
2 parts by weight of 2.8% ammonia 
10 parts by weight igniter mixture 

Two of these components are mixtures which 
are prepared as follows: 

Ethyl Silicate Solution. The S-1053 solution 
is completely hydrolyzed ethyl silicate which is 
stable for only short periods of time and so is 
made from a partially hydrolyzed formula (S- 
1003) which is stable during storage. 

334 CONCLUSIONS 

1. A unit composed of trioxane as the fuel 
ingredient, magnesium stearate as the support¬ 
ing agent, and carbon black as the pigment was 
recommended to the Quartermaster Corps. 
This trioxane fuel more closely fulfills the re¬ 
quirements for an army combat fuel than any 
of the others investigated. 


2. Sources of the trioxane fuel ingredients, 
methods of manufacture, burning characteris¬ 
tics, and physical properties were outlined. 

3. An alternate fuel of Carbowax 4000 and 
ethyl silicate was submitted to the Quartermas¬ 
ter Corps. 

4. As a result of the field trials on fuels, the 
following changes were recommended for the 
trioxane fuel unit. 

a. In order to prolong the burning period, 
the size of the unit should be altered to 
provide a thicker cake, changing from 2 3 / 16 
x 1% 6 x i /2 in- to 1% x 1 x % in. or 1% x 
1 x 1 in. 

b. If possible the metal foil wrapper of the 
trioxane unit should be so fabricated that 
it can remain around the sides of the fuel 
during its combustion. This will provide 
some wind protection and a longer burn¬ 
ing period. 

5. No satisfactory method was devised for 
overcoming the faults of the present commer¬ 
cially available fuels: soot and flame luminosity 
from paraffin wax, necessity of packing alco¬ 
hol gel in a can, and the toxic fumes from hexa- 
methylene tetramine. 

6. If the failings of any one of the commer¬ 
cial fuels are relegated to a position of unim¬ 
portance, that fuel will become satisfactory for 
use. 



Chapter 34 


LITERATURE SEARCH ON CARBONACEOUS FUELS 
FOR HEATING COMBAT RATIONS 


341 SUMMARY 

A SEARCH OF the technical literature (1920- 
1943) on the combustion of carbonaceous 
fuels revealed that charcoal was the most prom¬ 
ising for use in a fuel unit to heat army com¬ 
bat rations. The most active catalysts for car¬ 
bonaceous fuels, i.e., alkali carbonates, would 
add greatly to the luminosity of the flame, and 
there were no indications that they would lower 
the ignition temperature or accelerate the rate 
of combustion of charcoal to the degree desired 
in an army fuel unit. Recommendation was 
made that a highly porous charcoal fuel unit, 
preferably made of powdered or granular char¬ 
coal with a combustible resinous binder, be con¬ 
sidered. 


34 2 PURPOSE AND SCOPE OF THE 
LITERATURE SURVEY 

This search was undertaken to review pub¬ 
lished information on the combustion of car¬ 
bonaceous materials which might be applicable 
to a fuel unit for heating army combat rations. 
Special attention was given to catalysts which 
might provide the essential features of lower¬ 
ing the ignition temperature and accelerating 
the combustion of these materials. Chemical 
Abstracts were reviewed from 1920-1943 under 
the following subjects: briquets, carbon, catal¬ 
ysis, catalysts, charcoal, coal, coke, combus¬ 
tibles, combustibility, combustion, fuels, ignit¬ 
ers, ignition, inflammability, oxidation, and 
promoters. Many of the original articles deal¬ 
ing with extensive investigations were read. 
In addition to information on the most com¬ 
mon carbonaceous materials such as carbon, 
charcoal, coal, and coke, references were col¬ 
lected on certain subjects of interest to the 
fuel unit problem, i.e., solidified alcohol and 
metaldehyde. 


343 DISCUSSION OF THE LITERATURE 
SURVEY 

A discussion of the data compiled from the 
536 literature and patent references covered 
in detail the following subjects: combustion, 
oxidation reactions, ignition temperature, re¬ 
activity of fuels, combustibility, effect of dif¬ 
fusion of oxygen on the rate of combustion 
of solid fuels, effect of catalysts on ignition 
temperature, reactivity and rate of oxidation 
or combustion, mechanism of catalysis in 
combustion, miscellaneous non-catalyzed solid 
fuels, briquets (non-catalyzed), and special 
fuels such as alcohol, polymeric organic fuels, 
liquid and solidified hydrocarbon fuels poten¬ 
tially applicable to the army fuel unit. 


344 RESULTS OF THE SURVEY 

Combustion and oxidation of carbonaceous 
fuels: 

1. Low-temperature charcoal is the most 
promising carbonaceous fuel. It has the low¬ 
est ignition temperature, highest reactivity, 
lowest air supply required to maintain com¬ 
bustion, and the most extensive surface. 

2. The rate of combustion of solid fuels is 
limited by the rate of diffusion of oxygen 
through the stationary gas film on the surface. 

3. The most important factors in obtaining 
low ignition temperatures, high reaction to 
C0 2 , and rapid combustion are low carboniza¬ 
tion temperatures and large surface per unit 
volume. 

4. The terms and tests usually employed to 
evaluate carbonaceous fuels have been designed 
to indicate their performance in beds of fur¬ 
naces; no tests indicate their behavior when 
a match flame is applied to an individual piece 
of fuel. For heating army combat rations, an 
individual piece of fuel is required. 


158 


RECOMMENDATIONS 


159 


5. The results of investigations of ignition 
temperatures, reactivity, and combustibility of 
fuels, as well as the effects of catalysts on these 
characteristics, are not all comparable, because 
they depend upon the techniques employed by 
the various investigators. 

Catalysis in combustion and oxidation of car¬ 
bonaceous materials: 

6. Alkali carbonates are the best general 
catalysts for lowering ignition temperatures, 
increasing reactivity to C0 2 , and promoting 
combustion of fuels in beds. Calcium oxide and 
iron oxide are less effective, especially in re¬ 
ducing ignition temperatures. In addition, they 
would add greatly to the luminosity of the 
flame. 

7. The mechanism of catalysis has been in¬ 
dicated to be reduction to metallic sodium or 
iron in the lower sections of the fuel bed, then 
vaporization or transfer to the upper bed where 
the oxide is again formed. The applicability of 
such a mechanism to small fuel units is not 
clear. 

8. The effect of catalysts on burning rate 
decreases with the more reactive fuels, i.e., it 
is less for low-temperature cokes and char¬ 
coals. 

9. Impregnation is preferable to surface ap¬ 
plication of catalysts, to avoid shielding and 
blocking the reaction of oxygen and carbon on 
the surface. 

10. No evidence was found to indicate that 
any organic catalysts would lower the ignition 


point and accelerate combustion to the degree 
desired in the army fuel unit. 

345 RECOMMENDATIONS 

The most active solid fuel available in quan¬ 
tity should be used, i.e., charcoal. Since the 
limiting factor in combustion is the rate of 
diffusion of oxygen to the surface, a highly 
porous structure should be obtained. This 
might be achieved by providing a number of 
channels through a charcoal block, i.e., analo¬ 
gous to the form in which smokeless powder 
is prepared. Alternately, powdered or granu¬ 
lated charcoal might be bonded with a combus¬ 
tible resinous binder. The preferred process 
would be to form a rigid block without destroy¬ 
ing the porosity or blocking the surface of the 
charcoal. The bonding agent might also be of 
help in igniting the block. The development of 
such a fuel should be undertaken by an organi¬ 
zation experienced in the manufacture of char¬ 
coals and, if possible, of resinous products. 

An extensive bibliography was compiled on 
combustion and oxidation of carbonaceous ma¬ 
terials, catalysts in combustion and oxidation 
of carbonaceous materials, non-catalyzed com¬ 
mercial products, reviews and general informa¬ 
tion, briquets (non-catalyzed), and special fuels 
(alcohol, polymeric organic fuels, etc.). There 
are 536 classified references given. 




Chapter 35 

FLAMEPROOFING OF TEXTILES FOR ARMY CLOTHING 


351 EVALUATION OF COMMON WATER- 
SOLUBLE FIRE RETARDANTS 

T he purpose of this investigation was to 
evaluate the relative flameproofness of fab¬ 
rics impregnated with common water-soluble 
fire retardants, using a modified 45 degree 
microburner flame test and the standard verti- 
cal-bunsen flame test. 

On the basis of the experimental data ob¬ 
tained, it appears that the modified 45 degree 
microburner flame test is the superior of the 
two, since it permits a separation of the better 
retardants into several groups, the members of 
each possessing similar flameproofing efficien¬ 
cies. The standard vertical-bunsen test, on the 
other hand, is only capable of classification into 
good, fair, and poor fire retardants. 

Considering the results obtained with the 45 
degree microburner flame test, the classifica¬ 
tion of the better flameproofing agents was 
found to be of the following order of effective¬ 
ness: 

1 . The mixtures of borax-boric acid in the 
ratios of 7:3 and 1:1, borax-boric acid-diam¬ 
monium phosphate mixtures in the ratios 
7:3:5 and 5:5:1, and the mixture of borax- 
boric acid-ammonium dihydrogen phosphate in 
the ratio 7 :3:1. 

2. Borax-boric acid-diammonium phosphate 
mixtures in the ratios of 1:1:1 and 1:1:2 and 
the borax-boric acid-ammonium dihydrogen 
phosphate mixture in the ratio 7:3:5. 

3. Mono- and diammonium phosphates alone 
and the sulfamate-type fire retardants. 

4. Ammonium sulfamate, ammonium molyb¬ 
date, ammonium sulfate and sodium tungstate. 

The above classification is based upon the 
charred area measurements which represent 
a measure of the resistance to flaming. The 
effectiveness in the prevention of afterglow 
produces a different classification. 

The 45 degree microburner flame test is su¬ 
perior to the vertical-bunsen test in that it al¬ 


lows a better separation of the water-soluble 
flame retardants into groups, the members of 
each being nearly equally effective. This test 
has the added advantage of being better able 
to measure afterflaming of short duration (1 
to 3 sec). 

Of the several retardants tested, borax-boric 
acid (1:1) is the most efficient on the basis of 
the resistance to charring, mono- or diammo¬ 
nium phosphate, the best with respect to after¬ 
glow, and borax-boric acid-diammonium phos¬ 
phate in a 1:1:2 ratio, the best when charred 
area, flaming and afterglow are considered 
equally important. 

For a given borax-boric acid ratio, the addi¬ 
tion of mono- or diammonium phosphate to the 
mixture decreases the afterglow but increases 
the charred area slightly. 

Mono-ammonium phosphate can be substi¬ 
tuted for diammonium phosphate in the borax- 
boric acid-phosphate mixtures with only a 
slight decrease in the flameproofing efficiency. 

352 INVESTIGATION OF THE FLAME¬ 
PROOFING OF COTTON FABRICS 

The test methods used for the determination 
of the effectiveness of flameproofing agents and 
treatments, which have been completely devel¬ 
oped, are included in this report. The methods 
described are as follows: 

1. Impregnation of cotton fabric with 
water-soluble flame retardants. 

2 . Vertical-bunsen flame test. 

3. 45 degree microburner flame test. 

4. Laundering test. 

5. Leaching test. 

6 . Tensile strength test. 

7. Pyrolysis test. 

8 . Combustion test. 

9. 30 degree flame-rate test. 

10. Heating curve measurement (pure re¬ 
tardants) . 


160 


TRACES OF FIRE RETARDANTS ON COTTON FABRICS 


161 


Experimental methods and equipment for 
the tests are included. These tests constituted 
the official methods adopted by the project. 


35 3 EVALUATION OF COMMERCIAL 
FLAME RETARDANTS AND 
FINISHED FABRICS 

The object of this part of the investigation 
was to evaluate the relative flame-retardant 
efficiencies of commercially developed fire re¬ 
tardants for treated fabrics. Individual reports 
are available on the comparative evaluation of 
CM, Bancroft fabric, phosphamates, Pollack 
fabric, Montgomery Bros, treated fabric, 
Chemical Warfare Service-Massachusetts In¬ 
stitute of Technology treated fabric, Flamex, 
Chemical Warfare Service gasproofed-flame- 
proofed fabric, Ellicote P-1, Flamort T.C., 
Southern Regional Laboratory treated fabric. 

In the case of each commercial flame retar¬ 
dant and finished fabric tested, conclusions and 
recommendations are presented. 


33 4 THERMAL DECOMPOSITION OF 
FIRE RETARDANT MATERIALS 

The mechanism of the decomposition of 
cellulose at high temperatures was studied and 
the influence of various retardant chemicals 
determined. 

At elevated temperatures (500 C), cellulose 
decomposes into three main fractions: 

1. A charred residue composed mainly of 
carbon. 

2. A tarry distillate of a highly inflammable 
nature. 

3. A volatile fraction composed of water and 
fixed gases. 

In the presence of typical fire retardant 
chemicals, such as borate mixtures and phos¬ 
phates, the course of the decomposition of 
cellulose is radically changed. The charred 
residue is increased, tarry products are reduced 
to a very low amount, and the water plus gas 
fraction is substantially increased. 

These marked changes in the ratio of the 
three types of decomposition products take 


place upon the addition of up to approximately 
5 per cent of the effective fire retardants. 
Further addition of retardants does not ap¬ 
preciably affect the course of the reaction. 


353 VOLATILE DECOMPOSITION 
PRODUCTS FROM FABRICS 

During the pyrolysis and controlled com¬ 
bustion of fabrics, the volatile products consist 
of: 

1. A highly inflammable tarry distillate. 

2. An aqueous fraction. 

3. Smaller quantities of permanent gases 
consisting of water solubles (probably lower 
aldehydes and acids) CO, C0 2 , and hydrocar¬ 
bons. 

Fire retardants markedly reduced the 
amount of tarry distillate. The amount of 
tarry distillate is directly related to the flaming 
tendencies of the fabric. The inflammable tar 
must be reduced below 2 mg per sq cm of fabric 
to provide adequate protection against flaming. 
Both retardants and non-retardants increased 
the amount of water and permanent gases, and 
changed the composition of these gases. There 
appears to be no definite relationship between 
these gases and the flaming tendencies of the 
fabric. 


336 EFFECT OF TRACES OF FIRE 
RETARDANTS ON COTTON FABRICS 

Traces of fire retardant chemicals such as 
CM or ammonium dihydrogen phosphate added 
directly to a fabric or remaining after leaching 
of an effectively treated fabric have the follow¬ 
ing effects on the flameproofing: 

1. They may increase the rate at which a 
flame propagate along the fabric to a value 
equal to twice that at which an untreated 
fabric is consumed by the flame. 

2. They may increase the duration of the 
afterglow to give glowing times approximately 
double those of untreated fabric. 

Traces of retardants remaining in fabrics 
after the major amounts have been removed 
by water leaching have a definite detrimental 



162 


FLAMEPROOFING OF TEXTILES FOR ARMY CLOTHING 


effect on the fire resistance of the fabric. Less 
protection may result than that given by un¬ 
treated fabric. 


35 7 FUNDAMENTAL ASPECTS OF UREA- 
PHOSPHATE FLAMEPROOFING 

Urea-phosphate flameproofing functions by 
the fixation of phosphate within the fabric as 
an ester of cellulose. Normally, this ester exists 
as the nitrogen salt of the unreacted phos¬ 
phoric acid groups, and is capable of ion ex¬ 
change. The exchange, principally with calcium 
and magnesium ions, results in loss of the 
flameproofed qualities of the fabric if the 
nitrogen-phosphoric acid content falls below a 
critical value. 

The factors influencing the resistance to ion 
exchange are the original bath composition, the 
cure temperature, and the cure time. For per¬ 
manence toward sea water and laundering, the 
most favorable conditions are high concentra¬ 
tion of urea in the bath, high cure temperatures 
and long cure times. These conditions, pre¬ 
sumably, convert the nitrogen salt to the non¬ 
exchangeable amide. 

A formulation is recommended for flame¬ 
proofing cotton fabrics to give sufficient per¬ 
manence to withstand cold and hot water wash¬ 
ing, 2 hours tumbling in sea water and six 
launderings with GI soap. 


358 RATES OF DEGRADATION OF 
FLAMEPROOFED FABRICS 

The thermal behavior of fabrics at high tem¬ 
perature indicates the following: 

1 . Fabrics decompose in two main stages, 
one associated with the disintegration of the 
cellulose, the other associated with the oxida¬ 
tion of the products of the primary dissocia¬ 
tion. 

2 . These two stages coincide with the after- 
flaming and afterglowing tendencies of the 
fabrics. 

3. Fire retardants decrease the thermal in¬ 
tensity of these two reactions as well as their 
rates. 


4. The reaction most retarded corresponds 
with the afterflame or afterglow prevention 
qualities of the retardant, as measured by 
standard flame tests. 


35 9 INSULATION VALUE OF FLAME¬ 
PROOFED FABRICS 

The protection afforded by flameproofed 
fabrics during contacts with heat sources of 
high intensity was determined. It was found 
that untreated 81 / 2 -oz. herringbone twill 
offered appreciable protection against intense 
heat, provided the exposure is of short dura¬ 
tion and does not raise the fabric to the igni¬ 
tion temperature. Herringbone twill, which is 
both adequately flameproofed and glowproofed, 
exhibits much greater insulation against heat 
or flame than a comparable fabric which is 
highly flame resistant, but does not possess 
sufficient resistance to afterglow. An efficiently 
flameproofed herringbone twill exhibits thermal 
insulation comparable to an asbestos sheet of 
approximately the same weight and thickness. 
Certain types of treated herringbone twill are 
equal or superior to Fiberglas asbestos or 
Fiberglas-Neoprene fabrics in their ability to 
insulate against heat or flame. This is true 
whether the fabrics are considered as single 
ply or two- or three-ply systems. 

Fabrics which are highly flame resistant and 
also possess good resistance to afterglow offer 
a two-way protection against heat or flame. 
The wearer gains precious seconds of additional 
escape time by virtue of the low conductivity 
of the garment and, once removed from the 
source of heat, is not exposed to danger of 
burns from flaming or glowing clothing. 

Military clothing, flameproofed by the 
UDAP or Bancroft type of treatment, appears 
to be the best available solution to the problem 
of protection against flame attack. 


3510 CHEMICAL AND PHYSICAL 
PROPERTIES OF FLAMEPROOFING AGENTS 

The chemical and physical properties of the 
better flameproofing agents and mixtures were 



KINETICS OF THE OXIDATION OF CARBON 


163 


collected and tabulated. The data were avail¬ 
able as an aid in the investigation of the mech¬ 
anism of flameproofing. 

The properties of the following simpler 
flameproofing agents were studied: 

Borax. 

Boric acid. 

Borax: boric acid (7:3). 

Borax: boric acid (1:1). 

Borax: boric acid (3:7). 

Borax: boric acid: diammonium hydrogen 
phosphate (7:3:5). 

Ammonium sulfamate. 

Ammonium dihydrogen phosphate. 

Diammonium hydrogen phosphate. 

du Pont CM. 

du Pont CM — modified. 

du Pont 3-WG. 

du Pont T. 

Ammonium chloride. 

Ammonium bromide. 

Ammonium iodide. 

Urea. 

Urea:phosphate (2:1 molar). 

Urea:phosphate (4:1 molar). 

Urea:phosphate (6:1 molar). 

Urea:diammonium phosphate (4:4:1 molar) 

The major portion of the experimental work 
was concerned with the measurement of pH 
of aqueous solutions, the solubility of flame¬ 
proofing agents and their behavior on being 
heated up to temperatures approximating that 


of a flame. The heating characteristics were 
determined by visual heating experiments and 
more precise heating curve measurements. 

MM 

3511 KINETICS OF THE OXIDATION 
OF CARBON 

Glow retardants appear to function by 
effecting the course of the oxidation of the 
chars remaining after the flaming reaction. 
The chars from glowproofed fabrics are pref¬ 
erentially oxidized to CO, rather than to C0 2 . 

The heat liberated in the reaction to CO ap¬ 
pears to be insufficient to propagate a glowing 
reaction after the instigating source is re¬ 
moved. The reaction of the higher exother- 
micity (C0 2 ) appears to be the self-sustaining 
glow reaction. The mechanism whereby such 
reactions are favored by boric or phosphoric 
acid generating materials appears to be cata¬ 
lytic. The reaction is essentially independent 
of the catalyst concentration (above 1 per 
cent), and is readily capable of being poisoned 
by sodium salts. Sodium salts poison the boric 
acid catalyst more readily than they poison 
the phosphoric acid catalyst. 

The tenacity with which the phosphoric and 
boric acids are held on the chars indicates that 
the mechanism is associated with a surface 
catalysis phenomenon. The data are insufficient 
to determine the type of sorption involved. 





Chapter 36 


ORGANIC COATINGS 


36-1 SUMMARY 

A research program was planned for the 
development of organic coatings for 
metals, which would be rust inhibiting, easy to 
apply, and produced without the use of any 
critical materials. Since at the time the tung 
oil supply was very critical, it seemed neces¬ 
sary, especially in the “Blitz” water can linings, 
to discontinue the use in such finishes. In addi¬ 
tion, it seemed desirable to study new oils to 
determine whether they could replace tung oil 
in several types of finishes required. 

A number of new oils were evaluated as tung 
oil substitutes in several types of finishes, espe¬ 
cially in water can linings. They passed the 
standard hot and cold water tests, and many 
showed no softening or discoloration when re¬ 
moved from the water. By using suitable 
resins, good alkali resistance was obtained. 
Many of these oils may be substituted for tung 
oil without loss of serviceability character¬ 
istics. 

In the study of air-drying food can coatings, 
finishes were developed which laboratory tests 
indicated are equal to the present type of finish 
in speed of drying and adhesion, and superior 
in durability and salt water resistance. No 
further conclusions can be made until large 
scale application and exposure tests have been 
made. Several of these finishes contained no 
alkyd resin. 

Considerable work was completed on baked 
finishes for the exterior of food cans. Salt 
spray and weatherometer data indicated that 
they were satisfactory for durability and salt 
water resistance. Finishes tested for detail 
passed fabrication tests, indicating that they 
are entirely satisfactory for use under specifi¬ 
cation CQD-201A. None of the experimental 
finishes proved to be equal to the standard in 
processing tests; however, they were equal to 
the standard when applied at equal film 
weights. Some adjustment in pigmentation will 


need to be made so that experimental finishes 
will give satisfactory covering when applied at 
the same film thickness as the present material. 

Based on laboratory prepared finishes, nine 
experimental water can linings were prepared 
on a commercial scale and tested by the Quar¬ 
termaster Corps in accordance with specifica¬ 
tion JQD-111C. All except one of the experi¬ 
mental finishes, which were made with rela¬ 
tively available material, were found to be 
fully equivalent to the present tung oil type. 


2 EVALUATION OF SPECIAL OILS AS 
SUBSTITUTES FOR TUNG OIL 

Many oil companies have been actively 
engaged in developing oils which would give 
characteristics similar to those imparted by 
tung oil, including dehydrated castor oils, con¬ 
jugated oils made from linseed oil or soybean 
oil, oils consisting of pentaerythritol, sorbitol, 
esters of fatty acids, and fractionated oils. The 
specific oils used were dehydrated castor oil, 
Kellin, du Pont GF-35 oil, Atlas Powder “K” 
oil, Roosenol 200, Zymol, Heyden 395 oil, Bake- 
lite Modified linseed oil 1, Falkwood, Spencer- 
Kellogg Experimental oil XA-1, Conjulin, 
Spencer-Kellogg Experimental oil T-2, Roose¬ 
nol 100, and Select Oil 200 (Pittsburgh Plate 
Glass Co.). These oils were combined with 
several types of resins to make varnishes of 
varying oil length. The following resins were 
used: unmodified phenol formaldehyde (p- 
phenylphenol) — Bakelite BR254, Beckacite 
254, unmodified phenol formaldehyde (alkyl 
substituted) — Arofene 775, Bakelite 4036, 
rosin modified phenol formaldehyde — Am- 
berol M-93, Aroehem 365, maleic anhydride — 
Amberol 801, Aroehem 605, Teglac Z-152, Pen- 
talyn G, ester gum — Reichholdt Chemicals 
No. 1201, Congo, fused — No. 5, Strook & 
Wittenburg. Most of the varnishes were 20 to 
25 gal in length. 


164 


EXTERIOR AIR-DRY COATINGS FOR FOOD CANS 


165 


36,21 Twenty to Twenty-Five Gallon 
Varnishes 

All varnishes passed the hot and cold water 
tests, many showing no effect when observed 
immediately after the films were removed from 
the water. Especially interesting, where ex¬ 
treme water resistance is desired, were Am- 
berol M-93 with du Pont GF-35 oil, Bakelite 
BR254 with du Pont GF-35, Bakelite BR254 
with modified linseed oil, Bakelite BR254 with 
Roosenol 200, Pentalyn G with du Pont GF-25, 
and Arochem 605 with Zymol. Finishes made 
with GF-35 and Falkwood were somewhat dark 
in color. The rate of bodying in the kettle was 
normal. The rate of bodying in the case of 
GF-35, Roosenol 200, and Conjulin were ap¬ 
proximately the same as that of tung oil. Fast 
drying, comparable to the 4-hr type of tung 
oil coatings, was secured with practically all 
the oils. The following were of particular in¬ 
terest : Amberol M-93 with Roosenol 200, Bake¬ 
lite BR254 with K oil, Pentalyn G with Kellin, 
Amberol 801 with Zymol, Bakelite BR254 with 
Zymol, Amberol M-93 with Conjulin, Teglac 
Z-152 with GF-35, Arochem 605 with T-2, and 
Pentalyn G with Heyden oil. A number of 
finishes made with these oils and with rosin 
modified phenol formaldehyde resins have 
good resistance to 2 per cent sodium hydroxide 
solutions; Amberol M-93 with Kellin, Teglac 
Z-152 with Roosenol 200, Arochem 605 with 
Roosenol 200, Amberol M-93 with T-2 were 
especially satisfactory. The finishes made with 
100 per cent phenol formaldehyde resins gave 
excellent resistance to 5 per cent sodium 
hydroxide. 


36.2.2 Thirty-Five Gallon Varnishes 

All varnishes passed both hot and cold 
water test. Amberol M-93 with Zellin, Bakelite 
BR-254 with Kellin, Bakelite BR-254 with 
Zymol, Bakelite BR-254 with K oil, and ester 
gum with Zellin were of special interest. Good 
resistance to 5 per cent sodium hydroxide was 
obtained in some cases. The rate of bodying in 
the kettle was about normal for quick drying 
varnishes. 


36.2.3 Fifty-Five Gallon Varnishes 

These finishes were prepared with only a 
few of the newer oils to see if they would meet 
the requirements of specification TT-V-121a. 
Their rate of bodying was satisfactory. All 
samples dried hard in 24 hours, were tack-free 
in 18 hours, and passed the water-resistance 
tests. Amberol M-93 with GF-35, and ester 
gum with GF-35 showed good resistance to 
dilute alkali. It was concluded that most of 
the newer oils used with rosin modified phenolic 
or maleic resins will produce satisfactory 
finishes of this type. 

Fast drying and satisfactory water-resistant 
finishes were made with Select oil 200 and 
Roosenol 100. Varnishes of good alkali resis¬ 
tance could be made with K oil, if the tem¬ 
perature were raised to 580 F. Finishes which 
were identical, except that in one case the top 
heat was 560 F and in the other 580 F, were 
compared. Those varnishes raised to 560 F 
gave only fair alkali resistance, while the 
others were excellent. The finishes made with 
Congo resin were dark in color but dried fairly 
rapidly. Fused Congo with GF-35, Fused 
Congo with Roosenol 200, and Fused Congo 
with T-2 set in 1% hours and dried hard within 
7 hours. All were satisfactory for water resis¬ 
tance, but poor in resistance to dilute alkali 
with the exception of Fused Congo with GF-35. 
Changes in driers used would give improved 
alkali resistance. 

In general, fast drying varnishes were for¬ 
mulated with the oils under investigation. The 
type of resin affects the speed of drying and the 
time of cooking in the kettle. Such finishes 
have satisfactory water resistance, and by 
selecting the proper type of resin good alkali 
resistance was obtained. 

These oils produced finishes which had most 
of the characteristics of tung oil varnishes. 
On account of the rate of bodying, the produc¬ 
tion per kettle will be very little less than with 
tung oil coatings. 

36 3 EXTERIOR AIR-DRY COATINGS 
FOR FOOD CANS 

Many types of quick drying materials were 
tested to develop a coating to meet require- 




166 


ORGANIC COATINGS 


merits of CQD 200-A Type II, which would be 
superior to the present type of finish in speed 
of drying, ease of application, adhesion, flexi¬ 
bility, and durability, and which would contain 
no nitrocellulose (and preferably no alkyd 
resin). Those coatings which show promise 
were pigmented to olive-drab 319 of color card 
supplement to specification 3-1. Those which 
appeared satisfactory for speed of drying, ap¬ 
pearance, and flexibility were applied to tin 
plate, and salt spray and weatherometer tests 
were pigmented to olive-drab 319 of color card 
XK-16700 and XK-16624 appeared promising, 
but in the early tests were difficult to pigment. 
A smooth enamel could be obtained when the 
pigment and the resin solution were ground 
together. Some blends of Cumar resins gave 
excellent results immediately after drying, but 
most became brittle after aging one week. None 
passed the weatherometer and salt spray tests. 

Films made with Vinylite VYHH dried 
rapidly, but possessed poor adhesion and flexi¬ 
bility. Excellent results were secured if these 
finishes were applied over a suitable primer. 
Satisfactory results were obtained with two 
Acryloid finishes. 

Several of the finishes examined appeared 
to be equal to the present type in speed of 
drying and adhesion, at least equally easy to 
apply, and superior in durability and salt 
water resistance. 


36 4 EXTERIOR COATINGS FOR 
FOOD CANS 

Oleoresinous varnishes were prepared using 
resins and oils which would be suitable for 
baking finishes. They were pigmented to meet 
the color requirements (olive-drab 319 of color 


card supplement to specification 3-1), applied 
to tin plates by roller coating, and tested for 
adhesion, flexibility, and water resistance. The 
only failures occurred at the double seaming 
of the can ends. This effect probably can be 
corrected by changes in pigmentation so that 
the film weights will correspond to those now 
in use. In the laboratory, where approximately 
equal film weights were used, the experimental 
finishes tested were at least as good as the 
standard in both fabrication and processing. 
All of these finishes passed fabrication tests. 
Several of the experimental finishes were 
almost as good as the present material and on 
some types of tin plate, some experimental 
finishes were rated higher than the standard. 


36 5 INTERIOR COATING FOR 
WATER CANS 

A finish to conform to specification JQD-111C 
should be reasonably light in color and have 
sufficient flexibility and hardness to withstand 
service conditions. It must satisfy specified 
resistance tests, impart no taste to coffee and 
lemonade, and be unaffected by a number of 
chemicals. It should also be applied by spraying 
and then baked at 375 to 425 F. Finishes were 
prepared, some containing varying amounts of 
melamine formaldehyde, pigmented, applied to 
metal containers, and tested. From the data 
obtained, it was concluded that the finishes 
made with the following oils are more suitable 
than the standard finish made with tung oil: 
XA-1, Zymol, Kellin, GF-35, and K oil. If more 
weight was given to the service test, Roosenol 
200 was also better than tung oil. The develop¬ 
ment of interior coatings for food cans was 
considered, but no program was initiated. 



Chapter 37 

COATED FABRICS AND THIN FILMS 


37.1 WATER VAPOR PERMEABILITY 
OF PLASTIC FILMS 

3711 The Determination of Water Vapor 

Permeability 

permeability relationship was estab¬ 
lished in terms of the solubility coefficient 
and diffusion constant. Experimental proce¬ 
dures for the evaluation of the permeability 
were discussed. Diagrams of a variety of per¬ 
meability and diffusion cells are included. 
Values are given for the permeability constant, 
diffusion constant, and solubility coefficient for 
a wide variety of polymer films. Consideration 
was given to the effects of thickness, pressure, 
and plasticizers on the permeability. 

3712 Temperature Dependence of Water 

Vapor Permeability 

The experimental results indicated that the 
temperature dependence of permeability was of 
such magnitude and varies so much from one 
film material to another that it was possible 
for one film to be a much better barrier at 
room temperature but quite the opposite at 
freezing temperatures. There are described a 
number of direct measurements of the influ¬ 
ence of temperature on water vapor permea¬ 
tion for a number of self-supporting films. 

3713 Permeability Relation and the Effect 

of Plasticization 

The rate of permeation of a gas through a 
polymer as a function of temperature may be 
represented as 

P = P o 6 —e/rt 

All available data on permeability of gasses 
through polymers showed that for a given gas 
there was a linear relationship between P Q and 
E (the energy of activation). An explanation 
was offered for this apparent relationship. The 
effect of plasticization on the permeation of 
water vapor was studied experimentally and it 


was shown that the lowering of the heat of 
solution was the predominant effect. From 
the data, the entropy of solution may be cal¬ 
culated and was interpreted as showing that 
water molecules, dissolved in polymer, exhibit 
much less freedom than when they are dis¬ 
solved in plasticized polymer. 

37 2 VISCOELASTIC PROPERTIES OF 
PLASTICIZED VINYL FILMS 

37.2.1 Transition Phenomena in High 

Polymers 

The significance of first order and second 
order transition points was considered. The 
effects of molecular weight, crosslinking, 
copolymerization, and plasticizer action on the 
apparent second order transition were dis¬ 
cussed. The observed properties of an elastomer 
may be considered in terms of a molecular 
model in which there exists a range of internal 
and external Brownian movement. The inter¬ 
nal Brownian movement or “local” fluidity is 
responsible for the contraction of the stretched 
material while the degree of external Brown¬ 
ian movement measures the degree to which 
the material will flow. Crosslinking procedures 
fixed strong chemical bonds between individual 
chains which allow for the rapid extension and 
contraction of the sample, if local viscosity is 
sufficiently low, while the ties between molecules 
prevent permanent flow in the sample as a 
whole. 

37.2.2 Theoretical Discussion of 

Viscoelastic Behavior 

A theoretical treatment of the nature of 
stress and strain and their resolution into 
volume and shear effects is presented. The 
response of a viscoelastic material to a simple 
shearing stress was considered in terms of a 
Maxwell and a Voight element. The simple 
stress considerations were generalized to in¬ 
clude combined and inhomogeneous stresses. 



167 



168 


COATED FABRICS AND THIN FILMS 


37.2.3 Discussion and Illustration of 
Experimental Procedure 

The experimental technique for the measure¬ 
ment of tensile creep properties of films was 
described. The principal limitations of this 
method were: 

1. The lack of sensitivity of the method in 
the range of stiff materials. 

2. Variations in film thickness. 

3. Humidity control, found to be relatively 
unimportant for Vinylite films but extremely 
important for materials such as polyvinyl 
butyral. 

A comparison was made of the effects of 
the plasticization of Vinylite VYNW with 
tricresyl phosphate and trioctyl phosphate. At 
short times the response of the latter was 
greater, while the former sample deformed to 
a greater extent in response to stresses of long 
duration. The activation energy of viscous 
behavior was determined to be 80,000 calories 
and above. 

Curves of creep and recovery showed that 
within experimental error, the recovery curve 
may be predicted from a knowledge of the 
creep curve. 


37.2.4 The Effect of Plasticizer 

Composition on Creep Characteristics of 
Vinylite VYNW 

Plasticizers were divided roughly into four 
classes on the basis of the creep behavior which 
they impart to Vinylite VYNW: 

1. Steep—high curves. 

2. Steep—low curves. 

3. Flat—high curves. 

4. Flat—low curves. 

The presence of ring structures in the plasti¬ 
cizer (i.e., tricresyl phosphate) produced curves 
of types 1 and 2. Plasticizers which sweat out 
belong usually to group 4. 

For a plasticizer made up of trioctyl and 
tricresyl phosphates, the creep curve at low 
temperatures was between those of the pure 
plasticizers but at an intermediate temperature 
the mixture produces the more flexible film. 
Two generalizations which may be made with 
some reservation are: 


1. That extreme softness or rubberiness may 
be obtained by the use of plasticizers such as 
trioctyl phosphate. 

2. A moderate degree of flexibility existing 
over a wide range of temperature may be ob¬ 
tained by the use of a mixture of solvent and 
nonsolvent (PD-16)-type plasticizers. 

Plasticizing action was considered as a 
dynamic process of diffusion of plasticizer, 
which by migration causes the breaking and 
reforming of polymer-polymer contacts. 


37.2.5 The Effect of Resin Composition 
on Creep Characteristics 

Incorporation of Vinylite VYHH or VYNS 
into VYNW produced softer films at the ex¬ 
pense of flatness of the creep curve. Plasticized 
polyvinyl butyral was softer than Vinylite 
VYNW with the same amount of plasticizer. 
This softness was attained at the expense of 
the shape of the creep curve and the tem¬ 
perature dependence of the stiffness. 

Plasticization produced more than a lowering 
of the softening temperature of the Vinylite. 
The distribution of elastic relaxation was 
shifted to faster times and was spread out over 
a wider range of log t. In the case of nonpolar 
polymers, only the softening temperature was 
lowered. 

Concentrated solutions of Vinylite VYNW 
in a poor solvent (methyl ethyl ketone) gave 
greater viscosity values than solutions in a 
good solvent (cyclohexanone), due to molecular 
clustering in the poor solvent. The same 
general effects were observed in plasticizer- 
Vinylite solutions. 


37 3 SOLUTION PROPERTIES OF 
VINYL RESINS 

37.3.1 Theory of Polymer-Liquid Systems 

A theoretical treatment of polymer-liquid 
systems including recent extensions and modifi¬ 
cations concerning the entropy of dilution was 
presented. A molecular theory was presented 
for A H u the heat of dilution. Solubility con- 



SOLUTION PROPERTIES OF VINYL RESINS 


169 


siderations were extended to include the recent 
theories of fractionation. The importance of 
the compatibility constant was discussed. 

37.3.2 Fractionation and Distribution 
Curves of Vinyl Resins 

A detailed discussion was presented of the 
various experimental techniques of fractiona¬ 
tion used. It was determined that while frac¬ 
tional extraction procedures gave satisfactory 
resolution in the high molecular weight range 
and poor resolution in the low, the reverse was 
true of the fractional precipitation method. 

Distribution curves of Vinylite VYNW and 
Geon 101, as determined by the several 
methods, were presented. The distribution 
curve for both these polymers was sharp with 
a long low molecular weight tail. The number 
average molecular weights were reported as 
113,000 for Vinylite VYNW and 150,000 for 
Geon 101. 


37.3.3 Molecular Weight Technique 

Osmotic Pressure 

The report contains a brief summary of the 
theory of osmotic pressure. A complete discus¬ 
sion of the preparation and properties of deni¬ 
trated nitrocellulose and cellophane membranes 
is followed by a description of the construction 
and operation of the three types of osmometers 
used. 

Data are given for the number average mo¬ 
lecular weights for the various Vinylite and 
Geon resins, along with the molecular weight 
of several fractions. The molecular weight 
range of the Vinylite resins covers from 36,500 
for VYLF to 133,000 for Vinylite VYNW 998. 
Geon 101 and 202 have molecular weights of 
115,000 and 120,000, respectively. 

The solvent action, as determined from the 
slope of the tt/cc plot gives this order: Dioxane 
(poor), methyl ethyl ketone (fair), and cyclo¬ 
hexanone (good). 

Light Scattering 

The theory of the light-scattering technique 
and the experimental details are discussed 
briefly. 


Since the light scattering method was espe¬ 
cially sensitive to the state of molecular aggre¬ 
gation in the solution being measured, serious 
difficulties are encountered in the measurement 
of the molecular weight of Geon 101 and its 
resins. 

Values for the molecular weight of several 
Vinylite resins are given. Measurements of the 
dissymmetry of several of these solutions in¬ 
dicate that the polyvinyl chloride chains are 
much more extended than they would be if 
there were unhindered free rotation about the 
carbon-carbon bonds. 

Viscosity 

A brief treatment of the theory of viscosity 
is presented. The k' of the Huggins equation, 
on the basis of the experimental results, is in¬ 
terpreted as a constant whose magnitude 
depends, at least in part, on the number and 
permanence of contacts between adjacent 
solute molecules in solution, and its value is 
expected to decrease with increasing solvent 
action. 

Data are given for the intrinsic viscosity k' 
and vinyl acetate content for the several poly¬ 
vinyl chloride-polyvinyl acetate polymers in¬ 
vestigated. 

The relation between intrinsic viscosity and 
molecular weight for Vinylite VYNW fractions 
over the molecular weight range studied may 
be expressed as 

( v ) = KM a 

where 

K = 3.16 X 10- 6 
a = 1.1 


Association of Polyvinyl Chloride 
in Solution 


Measurement of the molecular weight of a 
Geon 101 fraction in dioxane, by the osmotic 
pressure technique, produced the values in the 
following table: 

Temperature, C Molecular Weight 
14 210,000 

38 210,000 

47 141,000 

68 112,000 

77 90,000 


Cl 



170 


COATED FABRICS AND THIN FILMS 


Osmotic pressure data for the same fraction 
in cyclohexanone gave molecular weights be¬ 
tween 94,000 and 98,000. The change of molec¬ 
ular weight with temperature in dioxane solu¬ 
tion was indicative of an association-disassocia- 
tion phenomenon. 

Similar effects are to be observed by light¬ 
scattering techniques for the Geon fraction in 
dioxane or in cyclohexanone to which non¬ 
solvent has been added. 

Examination of the Geon-dioxane system in 
the ultracentrifuge shows the presence of two 
components. The quantity of the heavier com¬ 
ponent decreases while that of the lighter com¬ 
ponent increases on heating. 

It appears then that a large portion of the 
polyvinyl chloride in Geon 101 has the ability 
to form associated clusters when dissolved in 
dioxane or in a similarly poor solvent. 

37.3.4 TJ ie Determination of Polymer- 
Liquid Interaction by Swelling 
Measurements 

For a large number of polymer-liquid sys¬ 
tems fi values have been determined by the ap¬ 
plication of the Flory-Rehner equation to the 
equilibrium swelling values of crosslinked poly¬ 
vinyl chloride film. Data are given for poly¬ 
vinyl chloride in a large number of liquids, 
with [x values ranging from 2.8 to —0.85. 

According to the data, fx was found to be 
temperature independent in the region 0.2 to 
0.4. Investigation of osmotic pressure data 
indicated the same boundary values for indiffer¬ 
ent solvents. For jx values less than 0.3, A H 
must be negative indicating strong polymer- 
solvent interaction. If fx becomes more positive 
(0.3 to 0.55), polymer-polymer contacts are 
preferred. Plasticizers with ^ values greater 
than 0.55 “sweat out.” 

With increasing temperature ix varied in 
such a manner as to approach a value between 
0.2 and 0.4. 


37.3.5 The Solubility of Polyvinyl 
Chloride Resins 

The minimum gel concentrations of Vinylite 
VYNW have been determined in a wide variety 


of solvents. The cohesive energy density of 
hydrocarbons and halogenated hydrocarbons 
was in the neighborhood of 90 cal/cc. Since 
the ix value of these systems was small, it is 
estimated that the cohesive energy density of 
polyvinyl chloride acetate was about 90 cal/cc. 
Using this value, other solvent systems were 
investigated. Ketones, esters, and nitro com¬ 
pounds were found to be active solvents, the 
specific forces probably being hydrogen bonds 
between the hydrogens on the chlorine carrying 
carbon and the negative oxygens of the solvent. 

For homologous series of plasticizers /x 
values have been determined. It appears that 
ix falls from a high value as molecular weight 
of solvent increases in a given series and then 
rises again. 

Dilution ratio measurements have been com¬ 
pared with jx values. For a series of comparable 
compounds the dilution ratio was found to in¬ 
crease as [x decreases. 


37 4 HEAT AND LIGHT AGING OF 
HIGH POLYMERS 

37,41 Theory of Aging 

A consideration of the elementary processes 
which occur during the aging of polymers was 
presented, along with chemical methods for the 
determination of chemical groups in polymers. 

The use of the infrared absorption spectrum 
to investigate the chemical changes during 
aging was presented along with a table of 
structural data for a variety of polymers. Con¬ 
sideration was given to the kinetics of oxygen 
absorption. 


37,42 Degradation of Vinyl and 
Diene Polymers 

Studies on simultaneous polymerization and 
degradation showed that a steady-state viscos¬ 
ity results in the presence of benzoyl peroxide. 
It follows that catalysts which decompose into 
free radicals may also catalyze degradation. 
This effect has been observed for polystyrene 
and methyl acrylate systems. 




HEAT AND LIGHT AGING OF HIGH POLYMERS 


171 


Factors affecting the rate of oxidation were: 

1 . Chemical structure. The double bond and 
methyl group of natural rubber enhance the 
rate of oxygen absorption. Replacement of the 
methyl group with Cl, CN, and amide, etc., 
resulted in a retardation of the rate of oxida¬ 
tion. 

2 . Antioxidants. The initial rate of oxygen 
pickup was greatest in a stock containing 
benzoyl peroxide and slowest in a stock con¬ 
taining phenyl /I-naphthylamine. The rate of 
stress increase was most rapid in the former 
showing that crosslinking and scission are 
accelerated by benzoyl peroxide and retarded 
by phenyl /?-naphthylamine. 

3. Vulcanization. Sulfurless hevea showed at 
least a sevenfold retardation in oxygen absorp¬ 
tion when compared to a similar sulfur cured 
stock. 


37.4.3 Evaluation of Light Sources 

It was determined that the rate of aging is 
dependent upon: 

1. The wavelength distribution of the inten¬ 
sity. 

2. The wavelength sensitivity of the polymer. 

Since it is believed that the existing discrep¬ 
ancies between sunlight-aged and artificially 
aged materials are due largely to variations in 
the characteristics of the light sources, an in¬ 
vestigation of those sources was made. Com¬ 
parisons are given between sunlight, National 
Fading Unit, and Atlas Fadeometer on the 
basis of the spectral intensity distribution. 

A sample calculation was included for the 
determination of the relative intensities of the 
different filter combinations. From these the 
total intensity over the entire spectrum may be 
calculated. 

37.4.4 Heat and Light Aging of 

Polyvinyl Chloride 

Polyvinyl chloride under heat releases HC1 
gas. The accumulation of HC1 results in an 
accelerated decomposition of the film. The 
presence of oxygen did not appear to affect the 
rate of HC1 release. 


Color changes on aging were attributed to 
an increase in the number and in the length 
of conjugated systems of double bonds. Sys¬ 
tems containing more than about five double 
bonds have a reddish color similar to that of 
aged polyvinyl chloride. 

The effects of a stabilizer appeared to be 
negative since it does not combine with the 
liberated HC1 and yet depressed the evolution 
rate below that of the unstabilized film when 
HC1 was not accumulating. 

The effect of ultraviolet light was to decrease 
the molecular weight of the resins. However, 
films exposed for elongated time periods 
showed a crosslinking effect. The presence of 
plasticizer reduced the amount of crosslinking 
without affecting the rate of chain scission 
markedly. 

It was found that wavelengths below 350 m^ 
are mainly responsible for breakdown. 

Exposure to ultraviolet light sensitized poly¬ 
vinyl chloride so that subsequent heating 
caused a marked breakdown. 


37.4.5 Ligto Aging of Synthetic Rubbers 

Outdoor exposure of rubber products caused 
degradation by three mechanisms: (1) ozone 
attack, (2) thermal oxidation, and (3) photo- 
activated oxidation. 

Elongation or flexure of samples was im¬ 
portant in ozone aging. Temperature had a 
very secondary effect. Ozone aging was a vital 
factor in the aging of natural and butadiene 
copolymer rubbers. It was of secondary im¬ 
portance for butyl, Neoprene, and polysulfide 
rubbers. Thermal oxidation in the absence of 
light was of importance for all rubber products 
used at elevated temperatures or whose use 
produced high temperatures. Infrared from the 
sun or from artificial sources caused apprecia¬ 
ble surface heating which accelerated oxida¬ 
tion. Photo-oxidation sometimes retarded ozone 
attack by forming an impervious surface skin. 

Many fillers, particularly carbon black, 
absorb most of the active radiation and effec¬ 
tively retard photo-sensitization. Many anti¬ 
oxidants which retard oxidation accelerate 
photo-oxidation. 




172 


COATED FABRICS AND THIN FILMS 


The effect of light appeared to be the accel¬ 
eration of oxidation without changing the 
nature of the aging process. Butyl rubber 
softens, and GR-S hardens, both by heat and 
light aging. The combined effect of both heat 
and light was greater than the sum of the 
individual effects. 

A rough proportionality existed between the 
total quantity of radiation and the extent of 
degradation. 


37 5 MECHANICAL PROPERTIES OF 
FILMS AND COATED FABRICS 

37,51 The Relationship of Mechanical 

Properties to Molecular Chain Lengths 
in Vinyl Polymers 

Fractions of Vinylite VYNW from the 
higher molecular weight range (upper 88 per 
cent of distribution curve) had an average 
folding endurance of 3,900 MIT double folds. 
This value was 90 per cent higher than the 
folding endurance for unfractionated Vinylite 
VYNW. The low molecular weight fractions 
had values of 510 to 610. The folding endur¬ 
ance becomes independent of molecular weight 
at about 130,000. Tensile strength falls off 
sharply as molecular weight decreases below 
80,000. 

Measurement of folding endurance and 
tensile strength for leached and vacuum dried 
films gave higher values of the former for 
leached and higher values of the latter for 
vacuum dried. It was evident that the method 


of preparation had a significant bearing on the 
mechanical properties. 

3752 Development of Films for 
Quartermaster Uses 

This section included an enumeration of the 
properties most desired in a film as well as the 
characteristics of a number of commercially 
prepared films. Tables of strength values of 
the differently prepared vinyl and polyethylene 
films were given along with aging and low- 
temperature characteristics. 

Saran-coated cellophane was found to be a 
superior packaging material for the wrapping 
of moisture containing materials. The loss of 
moisture, by weight, of the product wrapped 
in Saran-coated cellophane was shown to be far 
less than that of the same product wrapped in 
moistureproof cellophane. 

The methods of preparation of films on a 
laboratory scale are described in sufficient 
detail. Methods for the casting of plasticized 
and unplasticized vinyl films and rubber films 
are given. 

37.5.3 Developments in Coated Fabrics for 
Quartermaster Uses 

This section was concerned primarily with a 
discussion of the test data obtained in the 
evaluation program on poncho and raincoat- 
type materials. Tables of test data for alkyd 
modified oil-coated airplane cloth, polyvinyl 
butyral-coated fabrics, vinyl-coated nylon and 
cotton, etc., are given along with the discussion. 




Chapter 38 

WEAR RESISTANCE OF APPAREL TEXTILES 


38.i INTRODUCTION 

T he objects of this investigation of wear 
resistance of apparel textiles were: (1) to 
design a classification, scoring, and evaluation 
method whereby apparel textiles subjected to 
the Camp Lee Combat Course may be ranked 
for their wear resistance; (2) to study labora¬ 
tory abrasion-testing machines and techniques 
and develop laboratory criteria for ranking the 
abrasion-resisting properties of fabrics; (3) to 
correlate Camp Lee Combat Course results with 
laboratory abrasion-testing methods; and (4) 
to recommend improvements in fabric con¬ 
struction and/or finish which will increase the 
abrasion resistance of textiles in service. 

The Combat Course at Camp Lee, Virginia, 
was used to test the utility of military clothing 
and equipage under controlled and reproducible 
service conditions. The course consists of 
fences, road blocks, gravel roads, shell holes, 
concrete culverts, bombed out houses, rubble, 
etc., arranged so that the soldier passes through 
the obstacles chronologically and in a pre¬ 
scribed manner. 


38.2 XESX PROCEDURE 

This study was concerned with the wear re¬ 
sistance of apparel textiles tested upon the 
course and methods of correlating these results 
with abrasion resistance determined upon con¬ 
ventional laboratory abrasion-testing machines. 
Three cotton fabrics were studied: (1) 8.2-oz 
twill, (2) 9-oz sateen, and (3) 9.3-oz herring¬ 
bone twill [HBT]. Fifteen uniforms, i.e., a 
jacket and pair of trousers, were prepared 
from each fabric for the Combat Course test. 
All garments were made with warp yarns run¬ 
ning lengthwise. The twill and HBT were pre¬ 
pared face outward, the sateen back outward. 
Each soldier taking part in the test had one 
uniform of each fabric with which he made 
15 Combat Course traversals, wearing each 


i 

fabric in turn. At the end of each traversal, 
the garments were inspected and all damages 
recorded. They were then subjected to five 
more cycles. Analysis of the data was, how¬ 
ever, made only through the first fifteen cycles, 
since this was sufficient to determine fabric 
differences. 


383 COMBAT COURSE RESULTS 

Preliminary study of the fabrics subjected 
to the course showed the existence of funda¬ 
mental damage classes. (1) Wear areas: mild, 
medium, and severe; (2) Holes; (3) Holes in 
wear; and (4) Tears (considered a special type 
of hole). The size of each individual damage 
was calculated as the area of a rectangle of 
length and width equal to the maximum and 
minimum diameter of the damage area. 

By summing up areas of the same damage 
class, the Net Surface Damage [S] in square 
inches for each case was recorded at each cycle. 
A graph of S versus cycles was plotted, and 
the destructive index was calculated from this 
graph. To state that an end point alone ex¬ 
pressed in Combat Course cycles to produce 
any selected degree of destruction was a valid 
criterion of “wear resistance” is to neglect the 
importance of rate of destruction. Rate of 
destruction essentially measured the changing 
condition of the garment as it proceeds to 
destruction as a result of abrasion. The de¬ 
structive index was a number indicating the 
rate of damage to any garment at any cycle, 
taking into account the entire past history of 
the garment. The lower the destructive index, 
the better the garment. The destructive indices 
for each damage class for each fabric were 
calculated at each cycle. A combined destruc¬ 
tive index for all damage classes was calculated 
by weighting S for each damage class by its 
per cent reduction in warp tensile strength, 
summing the weighted S, and calculating a 
destructive index. 


173 


174 


WEAR RESISTANCE OF APPAREL TEXTILES 


Combat Course destructive indices showed: 
(1) the sateen wore out most slowly, and was 
therefore best; (2) herringtone twill wore 1.8 
times faster than the sateen, and was next 
best; (3) the twill wore out 2.1 times faster 
than the sateen, and was the poorest; (4) the 
twill probably wore out slightly faster than the 
herringbone twill (the difference between them 
was small compared with differences between 
twill and sateen and between herringbone twill 
and sateen). These conclusions apply to the 
twill face, herringbone twill face, and sateen 
back when the warp yarns run longitudinally 
in the garment. 


384 LABORATORY TEST RESULTS 

The Massachusetts Institute of Technology 
unidirectional and the Taber multidirectional 
abrasion machines were studied in the labora¬ 
tory. Samples of the three fabrics were abraded 
for a varying number of cycles, and the tensile 
strength of the abraded portions was deter¬ 
mined. Graphs of per cent loss in tensile 
strength versus abrasion cycles were then plot¬ 
ted for the following abrasion and test direc¬ 
tions for each fabric, face and back, for each 
of the two machines: (1) abrade warp-test 
warp, (2) abrade filling-test warp, (3) abrade 
filling-test filling, and (4) abrade warp-test 
filling. Areas under the per cent loss in 
strength versus cycles curve are laboratory 
destructive indices and may be compared with 
Combat Course destructive index values. 

Both the Massachusetts Institute of Tech¬ 
nology and the Taber machine ranked the abra¬ 
sion resistance of the fabrics in substantially 
the same order. Both show per cent loss in 
strength versus cycles curves of the same 
mathematical type, namely, C — e KL , where C 
is abrasion cycles, e the natural logarithm base, 
L the per cent loss in strength, and K a con¬ 
stant which varies with fabric geometry, abra¬ 
sion direction, and tensile strength direction. 
Therefore, no direct relationship between the 
Taber and the Massachusetts Institute of Tech¬ 
nology machine is known at present. 

Laboratory results indicated that fabrics 
abraded in different directions show the same 


resistance rank when tested in a single direc¬ 
tion ; fabrics abraded in a single direction show 
inverse abrasion resistance rank when tested 
in perpendicular directions. The sateen back 
when abraded and tested warpwise, and the 
twill face when abraded and tested fillingwise, 
were the most abrasion-resisting surfaces. 

The inherent abrasion resistances of the three 
fabrics were identical in that they were all 
made of cotton. Differences between the six 
surfaces were differences of fabric geometry, 
e.g., yarn size, twist, sett, diameter, fabric 
weave, picks and ends per inch, per cent warp 
or filling yarns on the fabric surface, and float 
length. Such noninherent fiber properties 
were collectively called form factor. This pro¬ 
cedure controlled the abrasion resistance of 
fabrics made from the same fiber. A fabric 
surface which had high abrasion resistance in 
one abrasion and test direction had poor abra¬ 
sion resistance in the perpendicular abrasion 
and test direction. If the six surfaces were 
abraded and tensioned equally in all directions, 
they should have equal abrasion resistances. 
This was demonstrated by summing the labora¬ 
tory destructive indices for the four abrasion 
and test directions. There resulted no signifi¬ 
cant difference in abrasion resistance rank be¬ 
tween the six surfaces. 

The fabrics had specific abrasion resistances 
for specific abrasion and test directions. To 
predict the abrasion resistance of a fabric 
under service conditions, the predominant abra¬ 
sion and tension directions must be known. 
Photomacrographs (19X) of each fabric were 
prepared to assist in interpreting the labora¬ 
tory abrasion results, Combat Course results, 
and the correlation between them. 

Analysis of the motion of the men as they 
traversed the course indicated that the direc¬ 
tion of abrasion and tension was predominantly 
longitudinal to the man. Since the garments 
were made with the warp yarns running 
lengthwise, it was predicted that the best 
course fabric would be that which was best 
able particularly to withstand warpwise abra- 
tion and tension. This prediction was con¬ 
firmed and explained by photomacrographs. 
The twill and herringbone twill face fabrics 
are warp flush. Warpwise abrasion during the 




CONCLUSIONS 


175 


course traversal caused severe warp yarn dam¬ 
age, resulting in warp failures under tension. 
The sateen back was a filling flush fabric; 
warp yarns under the same abrasion and ten¬ 
sion conditions were protected. 

Similarly, the laboratory abrasion resistance 
of every fabric surface for every abrasion and 
test direction may be predicted from photomac¬ 
rographs. Correlation between the prediction 
of Massachusetts Institute of Technology and 
Taber results was excellent. Course results 
show that the twill face and herringbone twill 
face have approximately twice the destructive 
index of the sateen back. For quantitative cor¬ 
relation, laboratory destructive indices should 
bear this same relation. If abrade warp-test 
warp laboratory destructive indices are com¬ 
pared, twill face-sateen back and herringbone 
twill face-sateen back ratios were much higher 
than the required 2:1. Therefore, other abra¬ 
sion and test directions must be considered to 
reduce these ratios until they become equiva¬ 
lent to course ratios. To arrive at proper ratios, 
empirically selected percentages of the various 
laboratory abrasion and test directions must 
be combined to form a weighted laboratory 
destructive index. Experimentally, it was 
found that if the following percentages of labo¬ 
ratory destructive indices for the four abrasion 
and test directions are calculated and summed, 
the resulting combined indices for the twill 
face, sateen back, and herringbone twill face 
are in approximately the same ratios in the 
laboratory as they are on the course: abrade 
warp-test warp, 70 per cent; abrade filling-test 
warp, 5 per cent; abrade filling-test filling, 20 
per cent; and abrade warp-test filling, 5 per 
cent. 

These weighting factors apply only when 
the warp yarn runs lengthwise with the gar¬ 
ment. Combat Course wear resistance of tex¬ 
tile fabrics may be predicted from laboratory 
criteria by the following method: If the warp 
yarns run longitudinally with the garment, sum 
the following destructive indices: abrade warp- 
test warp, 70 per cent; abrade filling-test warp, 


5 per cent; abrade filling-test filling, 20 per 
cent; abrade warp-test filling, 5 per cent. If 
the filling yarns run longitudinally with the 
garment, sum the destructive indices: abrade 
warp-test warp, 20 per cent; abrade filling-test 
warp, 5 per cent; abrade filling-test filling, 70 
per cent; abrade warp-test filling, 5 per cent. 
In both cases, the lower the resulting number, 
the better the abrasion resistance and the bet¬ 
ter the garment will wear on the course. 

385 CONCLUSIONS 

On the basis of percentages, the following 
conclusions and predictions were made: If the 
garment is constructed with the warp yarns 
running longitudinally, the sateen back will be 
best under Combat Course test; also if the gar¬ 
ment is constructed with the filling yarns run¬ 
ning longitudinally, the twill face will be best. 

Weighting values were empirically deter¬ 
mined after extensive study of the Combat 
Course and apply only to the course. It is 
neither stated nor implied that wear resistance 
under any and all service conditions may be 
predicted by the use of such weighting values. 
To predict wear resistance under service condi¬ 
tions from laboratory methods, a knowledge of 
abrasion and tension components for such con¬ 
ditions is necessary. Weighting values may or 
may not be the same as those found empirically 
for the course. The use to which the garment 
is put would decide whether Combat Course 
values might judiciously be applied. 

It is believed that, as a result of this in¬ 
vestigation, laboratory methods can now, with 
reasonable accuracy, predict the serviceability 
of fabrics with a minimum of effort and time, 
compared with the length and complexity of a 
Combat Course test. The Combat Course, how¬ 
ever, does more than evaluate fabrics. It judges 
clothing design and construction, utility of 
equipage, and aids in the solution of problems 
pertaining to comfort and convenience. It is 
doubtful whether laboratory techniques could 
ever solve such problems. 




Chapter 39 

SHRINKPROOFING OF WOOL KNITTED ITEMS AND FABRICS 


INTRODUCTION 

HE tendency of wool to felt under ordi¬ 
nary conditions of laundering is its out¬ 
standing disadvantage as a textile fiber, espe¬ 
cially when used in such items of clothing as 
socks, underwear, shirts, and sweaters. In nor¬ 
mal civilian uses, this disadvantage is in part 
overcome by extremely mild laundry conditions 
such as low temperatures and a minimum 
amount of mechanical action, conditions which 
are not obtainable under war operations. The 
military requirements for wool clothing are 
high, but these requirements have been greatly 
increased because of excessive shrinkage of 
these materials during field laundering. 

The research program on shrink-resistant 
treatments for wool was undertaken to over¬ 
come this difficulty. Shrink-resistant processes 
have been known for many years but, for a 
variety of reasons, have never achieved any 
appreciable success in the United States. Most 
of the known processes are included in the 
following main types: (1) halogenation proc¬ 
esses; (2) resin processes; (3) solvent-alkali 
processes; and (4) enzyme processes. 

The cushion sole sock was considered most 
critical and accordingly the problem of impart¬ 
ing a shrink-resistant finish to this item was 
attacked first. The urgency of this problem 
made it necessary to utilize or develop proc¬ 
esses which could be applied on equipment 
available in hosiery mills producing socks for 
military use. For this reason, considerable 
emphasis was placed on the halogenation proc¬ 
esses, although a number of the resin processes 
as well as the alkali-solvent process showed 
considerable promise. Of the last two, the 
former required special curing equipment and 
the latter a solvent recovery system, neither 
of which were available in hosiery mills. 

39 2 TEST METHODS 

It was well known that all the halogenation 
processes result in a certain amount of damage 


to the fiber; it therefore became necessary to 
have tests for measuring both shrinkage and 
fiber damage in order to determine the point 
at which the benefits of shrinkage resistance 
are offset by the disadvantages of reduced 
strength and elasticity which result from fiber 
damage. 

Test methods were developed for the follow¬ 
ing: measurement of shrinkage, laundry test, 
loss in weight, alkali solubility, 30 per cent 
index. This last measurement affords a very 
sensitive method for detecting changes in the 
fiber, but it does not tell what chemical re¬ 
action has occurred nor does it predict wear¬ 
ing qualities. These factors must be determined 
by correlation with other tests. 

39.3 INVESTIGATION OF SHRINIC- 
RESISTANT PROCESSES 

In order to minimize the time interval be¬ 
tween laboratory developments and practical 
application of such developments, a pilot plant 
was established. With these facilities it was 
possible to treat small commercial batches of 
socks under carefully controlled conditions. 

39,31 Halogenation Processes 

An investigation of various modifications of 
the halogenation processes was first under¬ 
taken. The processes investigated included: 
Hypol, Althouse, Lana-Seal, Neutronyx, West- 
vaco, Alrose, dry chlorination, alkaline hypo¬ 
chlorite, and acid hypochlorite. The Hypol 
process was developed and adopted as the pro¬ 
cedure recommended for mill trials on the 
cushion sole socks. 

39,3,2 Resin Processes 

The resin processes investigated were as fol¬ 
lows: Resloom, Lanaset, Dura-Lana. Although 
the results obtained with these resin processes 
were interesting, they were not recommended 



176 



FUNDAMENTAL RESEARCHES 


177 


because of certain disadvantages in the indus¬ 
try such as lack of curing equipment. 


39,3,3 Solvent-Alkali Process 

The Freney-Lipson process was investigated. 
The shrinkage control was very good and the 
damage was not excessive except at high tem¬ 
peratures and large moisture contents. 


393,4 Enzyme Process 

The only process investigated was the Ficin 
process, applied to wool after a pretreatment 
with sodium bisulfite. Socks treated by this 
process showed a large amount of fiber dam¬ 
age, and also shrank considerably. 

394 WEAR TESTS AT CAMP LEE 

In order to correlate laboratory tests with 
actual performance tests, socks were worn by 
men at Camp Lee. Some of these were deliber¬ 
ately overtreated in order to estimate what 
limits might prove practical. 


393 FUNDAMENTAL RESEARCHES 

The experiments were concerned with the 
practical aspects of treating wool in order to 
reduce its tendency to felt and shrink. Simul¬ 
taneously, some work of a more fundamental 
nature was conducted. 

When the effect of pH was investigated, it 
was found that the shrinkage during launder¬ 
ing decreased with decreasing pH of treatment. 


A number of preliminary experiments indi¬ 
cated that the reaction of the fiber with chlorine 
was influenced by the grade of wool (i.e., fiber 
diameter). In other words, in a given period 
of time, the finer fibers were affected to a 
greater degree than the coarser ones. The re¬ 
sults obtained indicated a direct relationship 
between 30 per cent index and fiber diameter. 

The idea has frequently been advanced that 
the nonshrinking characteristics of chlorinated 
wool are due to the fact that the scales are 
removed during chlorination treatments. Pre¬ 
sumably the fiber becomes smooth and will not 
migrate in the fabric. The effect of the treat¬ 
ments on surface structure was investigated 
on fiber treated in the pH series conducted at 
the pilot plant. The conclusion was reached 
that modification of the scale structure is re¬ 
lated to shrink resistance. 

The fact that certain treatments appeared 
to remove or damage the scales suggested, but 
did not prove, that the treated fiber was more 
slippery than the untreated fiber. In order to 
test this idea, a special instrument was de¬ 
signed for measuring the coefficient of friction 
of a single fiber against a wool felt or other 
surfaces. All values for the coefficient of fric¬ 
tion for treated fibers were higher than those 
for the corresponding untreated fibers within 
the limits of experimental error. The values 
measured dry did not change with pH of chlori¬ 
nation treatment, but those measured wet in¬ 
creased with decreasing pH and the low and 
high values tended to approach each other. This 
result means that not only is it more difficult to 
start the fibers in motion, but that they start 
as easily in one direction as in the other, thus 
eliminating any directional effect. The fric¬ 
tional properties are apparently important in 
the felting of wool. 




Chapter 40 

PACKAGING WITH PLASTICS 


401 INTRODUCTION 

V ARIOUS PLASTICS have been utilized in the 
form of thin film sheeting as wraps and 
bags during the past ten years. The recent 
developments in this field have produced pack¬ 
ages exhibiting improved functional character¬ 
istics, but in general the limitations applying 
to wraps and bags made of thin films remain. 
In view of the fact that a considerable number 
of industrial organizations have developed tech¬ 
nical skill in the handling of carton dipping 
processes, it appeared logical to seek further 
improvement of military packaging through 
the application of plastic materials in place 
of petroleum waxes. It was also known that 
there were many new chemical compounds 
under development in the laboratories of or¬ 
ganizations producing plastics, and that some 
of these new materials might have the char¬ 
acteristics desired for improving military 
packaging. 

The preliminary investigation under this 
project involved a survey of dipping composi¬ 
tions for application to packaging of rations. 
The objectives were as follows: 

1. To obtain available dipping formulations 
(products) from commercial sources. 

2. To set up a series of the most significant 
testing procedures for the relative evaluation 
of the above formulations. 

3. To evaluate the materials under (1) by 
the testing procedures established under (2), 
observing both the interesting and unsatisfac¬ 
tory characteristics. Among the properties 
evaluated were: 

a. Temperature of application and viscosity 
at application temperature, 

b. Blocking behavior at 140 F. 

c. The effect of handling at — 20 F on water¬ 
proofing. 

d. Water-vapor transmission, 

e. Odor and taste. 

f. Stability at application temperature. 


The desirable properties of the finished pack¬ 
age are as follows. 

1 . The material must be odorless, tasteless, 
and nontoxic. In the process of application, no 
undesirable odor or flavor should be transmit¬ 
ted to the contents of the package. 

2. A package dipped in the plastic should 
withstand storage at a temperature of 140 F, 
without blocking and without the liberation of 
solvents to contaminate the contents. 

3. The coating must be capable of withstand¬ 
ing rough handling at —20 F, without crack¬ 
ing, chipping, separation from the base paper, 
or loss of waterproofing. 

4. The coating should be impervious to the 
penetration of grease or oil. 

5. Water-vapor transmission rates measured 
in the General Foods Moisture-Vapor Trans¬ 
mission Cabinet should not exceed 0.1 gram 
per 100 sq in. per 24 hours. Materials with 
values up to 0.25 (comparable to those now in 
use) are of interest but substantial improve¬ 
ment is desirable. 

6 . The film should have good bursting 
strength, good tensile strength, and good re¬ 
sistance to tearing and abrasion. 

7. The coating must be waterproof at the 
temperature extremes mentioned and be stable 
to both fresh and salt water. 

8 . The film should be impervious to the gases 
ordinarily employed in chemical warfare. 

9. The coating must have good resistance to 
the penetration of insects and it is desirable 
that it be unattractive to rodents. 

10 . The film must be stable under field stor¬ 
age conditions for at least 24 months. 

11 . The coating should be transparent or 
sufficiently translucent to permit printing on 
the paperboard to be reasonably legible after 
application. 

12. The coating should not support the 
growth of fungi. 

13. The finished surface should preferably 
have a dull finish. Surfaces capable of reflect¬ 
ing light must be avoided. 


178 


DEVELOPMENT OF TEST METHODS 


179 


14. The coating should preferably be non- 
combustible, but slow-burning types are not 
prohibited. 

15. The film should be as nearly neutral as 
possible to avoid danger of corroding metallic 
containers used for ration components. 

Dipping or completely immersing a filled and 
sealed package in a liquid appears to be the 
least complex method of applying a continu¬ 
ous film. In view of the comparative simplicity 
of this procedure and the backlog of technical 
skill developed by various organizations in the 
handling of carton dipping, application by this 
method at speeds of 60 cartons a minute ap¬ 
peared to be the preferred approach. However, 
other methods of application are not excluded 
if their advantages justify modifications of 
technique. 

On the basis of use in a dipping process with 
a minimum change in existing procedures, the 
following properties should be considered: 

1. An application temperature of between 
180 and 210 F is desirable. One limiting factor 
here is the difficulty of obtaining bubble-free 
films at higher temperatures without predrying 
the paperboard. Another factor is the nature 
of the contents of the packages, which will in¬ 
clude biscuits, caramels, fruit bars, and choco¬ 
late. 

2 . At the application temperature, the vis¬ 
cosity should be sufficiently low to permit drain¬ 
ing of the excess material from the package. 

3. The material should be stable for periods 
up to two weeks at application temperatures. 

4. The coating should flow smoothly and 
bridge minor openings in the cartons. 

5. Wax compounds costing up to I 8 V 2 cents 
per pound have been used. Allowable costs of 
other materials will vary depending on the 
amount required, advantages gained, and sim¬ 
plicity of operation. 

Sixty-six commercial samples were received 
from industry as a result of a general request 
sent from the project. Twelve samples were 
believed suitable for test in the initial phase 
(hot melts) and forty-eight appeared interest¬ 
ing for compounding in the development phase. 
Six samples did not appear usable without some 
modification, such as the use of solvents or 
predrying of the cartons. 


402 DEVELOPMENT OF TEST METHODS 

Relations of Viscosity to 
Temperature 

One of the most significant properties in the 
preliminary evaluation of dipping materials is 
the relation of temperature to viscosity. For 
standard dipping techniques, a maximum tem¬ 
perature of approximately 220 F is allowed. 
Above this temperature, moisture in the carton 
will be removed, partially destroying the con¬ 
tinuity of the film. If a material is not liquid 
and sufficiently fluid at 220 F to permit dip¬ 
ping, special techniques would have to be em¬ 
ployed, such as predrying of the cartons and 
the use of higher dipping temperatures. These 
modifications are possible if justified by other 
advantages. The development of special dip¬ 
ping techniques was considered to meet un¬ 
usual requirements. 

A method employing the Brookfield Synchro- 
lectric viscosimeter was adopted for measur¬ 
ing temperature-viscosity relationships. This 
instrument utilizes a rotating spindle driven by 
a constant speed motor. Viscosities were mea¬ 
sured by the drag on the spindle and were in¬ 
dicated directly in centipoises. By the use of 
four different spindles and four different 
speeds, full-scale readings from 100 to 100,000 
centipoises were measured. 


4022 Blocking 

The blocking test consisted of a test on a 
coated piece of carton stock, subjected to a 
pressure of 1 psi for 24 hours at temperatures 
of 100 and 140 F. Nonblocking at 140 F is de¬ 
sired; the test at 100 F is included to allow 
more flexibility and an estimate of possible im¬ 
provement by modifications in the development 
phase of the program. 


40.2.3 r p] le Effect of Handling at —20F 
on Waterproofing 

Satisfactory moistureproofing of a coated 
carton cannot be obtained unless the film of 



180 


PACKAGING WITH PLASTICS 


wax or resin is continuous and unbroken. An 
unfortunate characteristic of many coating ma¬ 
terials is brittleness at low temperatures. Me¬ 
chanical handling at such temperatures (pro¬ 
duced by refrigeration, high altitude flight, or 
frigid weather) is likely to break a wax film. 
Subsequent exposure to atmospheric conditions 
of temperature and relative humidity then re¬ 
sults in an undesirably high pickup of moisture. 

Direct evaluations of resistance to such treat¬ 
ment involve numerous variables of applica¬ 
tion and handling, and are valid only for the 
conditions used. It was felt that a fundamental 
evaluation of the properties affecting such be¬ 
havior would be preferable to an arbitrary 
comparison of coated cartons. 

Among the factors governing the low-tem¬ 
perature behavior of a coated board are the 
following. 

1. The properties of the board. 

2. The anchorage of the wax or resin to the 
board, influenced by the viscosity of the wax, 
permeability and wettability of the board, and 
time of immersion. 

3. The low-temperature flexibility of the wax 
or resin film. 

4. The thickness of the film. 

Undoubtedly, the most important factor is 

the low-temperature flexibility. If the coating 
material is sufficiently flexible, stresses result¬ 
ing from differential contraction or from bend¬ 
ing will not cause fracture. On the other hand, 
if the coating is brittle, only a small thickness 
can be used without danger of fracture. All 
other factors being the same, a more flexible 
material can be employed in a greater thickness 
and, hence, will afford better protection against 
moisture transfer. 

The stresses which might break the wax film 
on a carton during shipment or handling are 
those associated with an object falling on, or 
against, the carton, or with the carton falling 
upon some object. Because there is reason to 
believe that flexibility of materials like waxes 
depends upon the rate of application of stress, 
static flexure tests are less suitable than dy¬ 
namic measurements. In view of this consid¬ 
eration, a method of measurement of flexibility 
was desired in which the stress is built up very 
quickly. 


The apparatus consists essentially of a pen¬ 
dulum which is freely suspended from a simple 
pin bearing (not lubricated). A clamp at the 
lower end of the pendulum grips one end of 
a strip of the wax under test. The pendulum 
is “cocked” at a rather large angle. After the 
specimen has been at the given low temperature 
for a time sufficient to be in equilibrium with 
the surroundings (the instrument is in an elec¬ 
tric cold box), the pendulum is released. At the 
bottom of the swing, where the pendulum has 
its greatest speed, the lower end of the speci¬ 
men meets a fixed anvil. The specimen strip 
then bends and breaks, the degree of bend to 
rupture depending upon the flexibility of the 
wax. 


40 2 4 Determination of Moisture-Vapor 
Permeability 

The intrinsic moisture-vaporproofing of the 
materials submitted was desired rather than 
the permeability of a coating of these materials 
on paper as applied under an arbitrary set of 
conditions. 

The measurement of moisture-vapor permea¬ 
bility by the usual gravimetric method with 
films of appreciable thickness would be very 
slow for those materials having moisture-vapor 
permeabilities sufficiently low to be of interest. 
Accordingly a dynamic method was developed, 
using an electric hygrometer. 


40 2 5 Stability at Application Temperature 

A test period of seven days at 212 ±2F was 
adopted for the study of the thermal stability 
of dipping compositions. 


4026 General Observations 

The importance of odors and toxicity was 
recognized; quantitative measurements were 
planned. Samples known to contain materials 
which would impart odor or toxicity were elimi¬ 
nated. 





SUMMARY 


181 


40.2 7 Fungus Resistance 

Three different organisms were studied, 
namely, Chaetomium globosum, Metarrhizium 
glutinosum, and Aspergillus ustus. The culture 
method of test was used and the relative tox¬ 
icity of thirty-two different materials recorded. 

40.3 SUMMARY 

A survey of available materials, suitable for 
use as hot melts at temperatures not over 220 
F, for improving the packaging of ration car¬ 
tons was completed. 

The need for methods of evaluation of funda¬ 
mental properties was obvious from previous 
experience. Six properties were selected for 
evaluation, including viscosity-temperature re¬ 
lations, blocking characteristics, low-tempera¬ 
ture flexibility, water-vapor permeability, sta¬ 
bility at application temperatures, and general 
observations on odor and taste, and methods 
were developed for their evaluation. New tech¬ 
niques for low-temperature flexibility and 
water-vapor permeability of the coating ma¬ 
terial (as distinguished from coatings pre¬ 
pared under arbitrary conditions) were adapted 
from other fields and developed to a point nec¬ 
essary for comparison of the submitted ma¬ 
terials. 

The low-temperature flexibility test mea¬ 
sured the extent to which a film of ma¬ 
terial will stretch before failure when loaded 
at a high rate of speed and at low tempera¬ 
tures (comparable to dropping a case in cold 
weather). 


The water-vapor permeability test was more 
sensitive than previous methods, detecting 
transfer of as little as 2 X 10 5 gram of mois¬ 
ture vapor through a sample 9 sq in. in area. 
The size of sample may be varied without seri¬ 
ously affecting the sensitivity of the test in 
grams per unit area, thus permitting large 
samples to be tested in order to get overall 
averages more quickly or permitting small 
samples to be tested when only such samples 
are available or convenient. 

None of the 12 samples submitted appeared 
suitable for immediate use. Only two hot melts 
showed any improvement in low-temperature 
flexibility over the paraffin-microcrystalline 
wax mixtures. These two materials had poor 
blocking characteristics at 140 F and viscosi¬ 
ties higher than the waxes. Three materials 
showed improvement in blocking; of these, one 
had a high viscosity and poor moisture-vapor 
resistance; the other two had poor low-tem¬ 
perature flexibility. 

The evaluation of the compounding agents 
submitted was started. Polyethylene and poly¬ 
isobutylene (of the molecular weights first sub¬ 
mitted) raised the viscosity of paraffin con¬ 
siderably when used in amounts of 10 to 15 
per cent but improved the low-temperature 
flexibility somewhat. 

A method for evaluating resistance of fungi 
to various toxicants was developed and applied 
to various materials, using Chaetomium globo¬ 
sum, Metarrhizium glutinosum, and Aspergil¬ 
lus ustus as test organisms. Investigations 
were also started on the mechanism of fungus 
growth on or in wax-dipped cartons, and or¬ 
ganisms inside the sealed carton were isolated. 



Chapter 41 


STORAGE OF CHLORINATED LIME 


411 SUMMARY 

A STUDY was MADE of the amount of heat 
liberated during the decomposition of 
chlorinated lime. The heat of reaction between 
chlorinated lime and several added impurities 
as well as the effect of varying moisture con¬ 
tent and the catalysis by iron and by ferric 
oxide were also investigated. 

The relative instability of chlorinated lime 
as a function of moisture content, as measured 
by the loss of available chlorine, can be ex¬ 
pressed as follows: 

1.5% : 5.0% : 10.5% :: 1.0: 5.2: 72. 

The amount of heat liberated during the de¬ 
composition of chlorinated lime, containing no 
added impurity, could not be determined by the 
methods employed. 

The following substances were tested for re¬ 
activity with chlorinated lime. They were 
listed in order of increasing activity, as mea¬ 
sured by the amount of heat liberated per gram 
of added impurity: a vinylite resin, a phenolic 
resin, iron, asphalt, oil, and paper pulp. The 
reactivity of paper pulp and of oil was greater 
in chlorinated lime having low moisture con¬ 
tent (1.5 per cent) than in that having high 
moisture content (10.5 per cent). The reactiv¬ 
ity of asphalt was lowered by decreasing mois¬ 
ture content. 

The presence of iron or of ferric oxide will 
catalyze the reactions between chlorinated lime 
and all of the above substances. However, only 
a very slight effect was noted in samples con¬ 
taining asphalt, the vinylite resin, or the phe¬ 
nolic resin. Catalysis was marked in samples 
containing paper pulp. The catalysis of iron 
and ferric oxide showed no dependence on mois¬ 
ture content. 

The temperatures at which the reactions be¬ 
tween chlorinated lime and the various impuri¬ 
ties became evident were as follows: In sam¬ 
ples containing 10.5 per cent moisture, paper 
pulp 35 C (95 F), oil 40 C (104 F), phenolic 
resin 85 C (185 F), vinylite resin 85 C (185 

182 


F), iron 95 C (203 F), and ferric oxide, no 
reaction determinable; in samples containing 
5.0 per cent moisture, no reaction was noted 
below 75 C (167 F) ; in samples containing 
1.5 per cent moisture, paper pulp 80 C (176 F), 
oil 85 C (185 F), the phenolic resin, the viny¬ 
lite resin, asphalt, iron, and ferric oxide, no 
reaction determinable. 

4i.2 INTRODUCTION 

This investigation was undertaken to extend 
the knowledge of the behavior of chlorinated 
lime during storage and to determine the fac¬ 
tors responsible for the exothermic decomposi¬ 
tion. The materials investigated were of the 
type known as Chamber Bleach, which is char¬ 
acterized by moisture content of 10 to 14 per 
cent, and Mechanical Bleach containing 5 per 
cent moisture or less. 

The hazardous properties of chlorinated lime 
may be caused by two general properties of 
the material. It is an oxidizing agent, and as 
such, will react with substances susceptible to 
oxidation, with the liberation of heat during 
the process. Oxidizable substances may become 
associated with chlorinated lime by their being 
present in the materials from which the lime 
is manufactured, by introduction during manu¬ 
facture, or because the chlorinated lime is 
stored in containers composed of reactive ma¬ 
terial. Common storage containers are iron 
drums and asphalt lined, iron ended, paper con¬ 
tainers. All these container materials are sus¬ 
ceptible to oxidation. Oil, an oxidizable sub¬ 
stance, possibly could be introduced from manu¬ 
facturing or packaging machinery. In addi¬ 
tion to being an oxidizing agent, chlorinated 
lime is unstable. It undergoes measurable de¬ 
composition at room temperature, with the 
liberation of chlorine and oxygen. It is entirely 
possible that either of these two processes, i.e., 
reaction with oxidizable materials or spontane¬ 
ous decomposition, may be catalyzed by impuri¬ 
ties normally associated with chlorinated lime. 




DISCUSSION OF RESULTS 


183 


41.3 EXPERIMENTAL PROBLEMS 

The experimental problems involved were to 
devise methods of determining the heat of de¬ 
composition of chlorinated lime, the heat of 
reaction of mixtures of chlorinated lime and 
oxidizable impurities, the relative rate of the 
various reactions and the temperatures at 
which the rates of the reactions became ap¬ 
preciable. The following factors were investi¬ 
gated : 

1. Condition and composition of various 
chlorinated lime samples as received from 
Quartermaster depots. 

2. The effect of moisture content on the de¬ 
composition of uncontaminated chlorinated 
lime. 

3. The effect of the presence of oxidizable 
impurities and varying moisture content on the 
decomposition. 

4. The heat evolved by the reaction of chlori¬ 
nated lime with various added impurities. 

5. The catalytic effect of iron and of ferric 
oxide on the decomposition of chlorinated lime 
in the presence of oxidizable impurities. 


41.4 DISCUSSION OF RESULTS 

The literature contained no reports of quan¬ 
titative measurements on the amount of heat 
liberated during the decomposition of chlori¬ 
nated lime. Contradictory evidence was pre¬ 
sented regarding the extent and rate of decom¬ 
position of the material. Nevertheless, the 
weight of evidence indicated that chlorinated 
lime may be expected either to lose available 
chlorine at the rate of from 0.5 to 2.0 per cent 
per month which appeared to result in no 
serious evolution of heat, or to decompose vio¬ 
lently within from 24 hours to several months 
after packaging, in which case the material 
would be a serious fire hazard. The 0.5 to 2.0 
per cent per month loss of available chlorine 
appeared to be the normal rate of decomposi¬ 
tion, which represented the inherent instability 
of the material, under normal storage condi¬ 
tions. The violent decomposition has been at¬ 
tributed to causes which include differences in 
manufacturing procedure, contamination by 


substances which act to catalyze the decomposi¬ 
tion, and reaction with substances susceptible 
to oxidation. 

Several instances have been recorded in 
which the stability of chlorinated lime has been 
stated to be inversely related to the moisture 
content of the material. The first phase of this 
investigation was an attempt to verify those 
observations, and further, to determine the 
effect of varying moisture content on the heat 
liberated during decomposition. The experi¬ 
ments indicated that the loss of available 
chlorine was inversely related to the moisture 
content. It should be realized that each of the 
samples was heated to 100 C (212 F), main¬ 
tained at that temperature for the same length 
of time, and sampled for analysis after cooling. 
The magnitude of the loss on heating should 
not be associated with loss under actual stor¬ 
age conditions. It indicated the relative sta¬ 
bility under conditions of the test. Should 
chlorinated lime behave in storage as under 
the conditions of the tests, the relationship 
between moisture content and loss of available 
chlorine would be as follows: 

1.5% : 5.0% : 11.0% :: 1.0: 5.2:72. 

However, despite the variation in stability 
with moisture content no evolution of heat 
could be observed during the decomposition. No 
attempt was made to trace the course of de¬ 
composition, so that a comparison with the 
various mechanisms of decomposition reported 
in the literature was not possible. 

It was established that chlorinated lime, un¬ 
contaminated by appreciable amounts of oxi¬ 
dizable materials, could not be responsible for 
the liberation of sufficient heat to be a serious 
fire hazard. Therefore, it seemed pertinent that 
the reactions between chlorinated lime and the 
materials of construction for storage con¬ 
tainers as well as substances likely to be found 
as contaminants, be investigated. The experi¬ 
ments described were designed to establish the 
resistance of paper, iron, asphalt, oil, ferric 
oxide, and two synthetic resins to oxidation 
(or chlorination) by chlorinated lime and to 
determine the effect of moisture content on 
the several reactions. 

The results of these experiments were not 
quantitatively applicable to actual storage con- 



184 


STORAGE OF CHLORINATED LIME 


ditions. The reaction between chlorinated lime 
and any solid component will depend on the 
surface of the substances in contact. No a 
priori statement can be made concerning the 
distribution of contaminants in the chlorinated 
lime as packaged. The test samples were pre¬ 
pared so that, so far as possible, the extent of 
surface of the materials in the mixtures was 
constant. In all samples tested the contaminant 
was evenly distributed throughout the mixture. 
When oil was the contaminant, the components 
were mixed by grinding. The conditions in the 
test samples represented the greatest area of 
contact between the chlorinated lime and the 
impurity for the state of subdivision of the 
components and therefore represented the 
optimum conditions for the reactions. 

The activity of the various impurities may 
be examined from two points of view. It may 
be reasoned that a substance is inactive if it 
does not react at an appreciable rate below a 
given temperature. This will be an important 
consideration in determining the maximum 
temperature allowed for storage, should a 
given impurity be present. Or, a substance may 
be considered inactive if the heat of reaction 
is low. 

From the point of view of the temperature 
at which reaction with the various impurities 
becomes evident, moisture content is an im¬ 
portant factor. Paper pulp will react at an 
appreciable rate with chlorinated lime contain¬ 
ing 10.5 per cent moisture at a temperature as 
low as 35 C (95 F), whereas if the moisture 
content is lowered to 5.0 per cent, reaction is 
not evident at 75 C (167 F), and in the 
presence of 1.5 per cent moisture reaction is 
not appreciable at 80 C (176 F). The reaction 
with oil, the next most active substance, be¬ 
comes evident at 40 C (104 F), 75 C (167 F), 
and 85 C (185 F) in chlorinated lime contain¬ 
ing 10.5, 5.0, and 1.5 per cent moisture, respec¬ 
tively. The reaction of the two synthetic resins, 
and asphalt with chlorinated lime containing 
10.5 per cent moisture could not be observed 
until heated to 85 C (185 F), while in the 
presence of only 1.5 per cent moisture no exo¬ 
thermic reaction was apparent up to 100 C 
(212 F). Iron presents a special problem. The 
rate of reaction with chlorinated lime is slow 


and little heat is evolved in samples containing 
10.5, 5.0, and 1.5 per cent moisture, at tempera¬ 
tures up to 100 C (212 F). However, iron and 
ferric oxide are active catalysts for the reac¬ 
tions between chlorinated lime and paper pulp, 
oil, and to a lesser degree with asphalt. 

The two synthetic resins were generally less 
active than the other substances tested. In the 
presence of 10.5 per cent moisture, reaction 
was not evident below 85 C (185 F) and no 
reactions were observed when the moisture 
was reduced to 1.5 per cent. Furthermore, 
neither iron nor ferric oxide had an apprecia¬ 
ble catalytic effect on the reaction of the resins 
with chlorinated lime. 


41 5 HYGROSCOPICITY AND RELATION¬ 
SHIP OF pH TO STABILITY 

A method for the determination of the 
hygroscopicity of chlorinated lime and calcium 
hypochlorite was developed. Standard labora¬ 
tory equipment was employed so that industrial 
laboratories could utilize the method without 
unnecessary delay. The equipment consisted of 
a constant temperature oven, glass desiccator, 
saturated KC1 solution and weighing bottles. 
The results of the investigation showed that, 
in general, samples of chloride of lime were 33 
to 100 per cent more hygroscopic than calcium 
hypochlorite. 

The relationship of the pH of the samples 
to their stability as measured by the loss of 
available chlorine on heating was investigated. 
Samples were adulterated with 5, 10, 15, and 
20 per cent of each of the following substances: 
quartz, calcium hydroxide, and boric acid. The 
quartz served as the inert diluent for com¬ 
parison measurements. The pH of the samples 
were not appreciably increased by the addition 
of 5 to 20 per cent calcium hydroxide. The 
addition of 5 per cent boric acid caused very 
little change in the pH; 10, 15, and 20 per cent 
boric acid affected the pH of the calcium 
hypochlorite to a greater extent than the 
chlorinated lime. 

The addition of varying quantities of cal¬ 
cium hydroxide to samples of calcium hypo¬ 
chlorite did not appreciably increase their 



GENERAL SPECIFICATIONS 


185 


stability. Samples of chloride of lime were 
decidedly stabilized to the loss of available 
chlorine on heating. The addition of boric acid 
had a marked detrimental effect on the sta¬ 
bility; the decrease in stability was caused by 
the presence of the boric acid rather than the 
effect of the boric acid on the pH. 

416 GENERAL SPECIFICATIONS 

This investigation suggested the following 
general specifications: 

1. Samples exposed to 90 per cent relative 
humidity at 35 C for 24 hr should not gain 
more than 85 per cent by weight for calcium 


hypochlorite and 100 per cent by weight for 
chloride of lime. 

2. The pH of the products should be between 
11.0 and 12.0. 

3. The moisture content should not be greater 
than 5 per cent for chloride of lime and cal¬ 
cium hypochlorite products. 

4. The lime used for manufacture should be 
free from iron, cobalt, and manganese. Con¬ 
tamination by organic substances such as oil 
and cellulose should be prohibited. 

5. The stability of the sample to the loss of 
available chlorine on heating should not be 
greater than 15 per cent for either the chloride 
of lime or the calcium hypochlorite. 







BIBLIOGRAPHY 


Numbers such as Div. 11-200-MI indicate that the document listed has been microfilmed and that its title 
appears in the microfilm index printed in a separate volume. For access to the index volume and to the micro¬ 
film, consult the Army or Navy agency listed on the reverse of the half-title page. 


Chapter 1 

1. Hydraulic Fluids, M. R. Fenske, Report 1, Pennsyl¬ 
vania State College, May 7,1941. Div. 11-200-MI 

2. Hydraulic Fluids and Recoil Oils, M. R. Fenske, 
OSRD 143, PRL-2, Sept. 23, 1941. 

3. Hydraulic Fluids, M. R. Fenske, OSRD 188, PRL-3, 
Dec. 8,1941. 

4. Hydraulic Fluids, M. R. Fenske, OSRD 459, PRL-4, 
Mar. 6, 1942. 

5. Hydraulic and Recoil Oils, M. R. Fenske, OSRD 695, 

OEMsr-408, Service Projects AC-7, AC-8, and OD- 
61, Report 284, Pennsylvania State College, June 30, 
1942. Div. 11-200-M2 

6. Hydraulic and Recoil Oils (Sixth Progress Re¬ 

port), M. R. Fenske, OSRD 1029, OEMsr-408, Serv¬ 
ice Projects AC-7, AC-8, and OD-61, Pennsylvania 
State College, Nov. 25,1942. Div. 11-200-M3 

7. Development of Hydraulic Fluids for Aircraft at 
Low Temperatures, Report MO-383, National Re¬ 
search Council of Canada, December 1942. 

8. Cold Weather Tests, Final Report on Hydraulic Sys¬ 
tems, Shock Absorber Struts, Brakes and Shimmy 
Dampers, Eng-M-51/4464-1-3, AAF, Wright Field, 
Mar. 18, 1943. 

9. Hydraulic and Recoil Oils (Seventh Progress Re¬ 
port, to Apr. 8, 1943), M. R. Fenske, OSRD 1369, 
OEMsr-408, Service Projects AC-7, AC-8, and OD- 
61, Pennsylvania State College, Apr. 27, 1943. 

Div. 11-200-M4 

10. Hydraulic and Recoil Oils (Eighth Progress Report 

for the period from Apr. 9, 1943, to Sept. 24, 1943), 
M. R. Fenske, OSRD 1894, OEMsr-408, Service 
Projects AC-7, AC-8, and OD-61, Pennsylvania 
State College, Oct. 6,1943. Div. 11-200-M5 

11. Development, of Special Recoil Oil, AXS-808, Fuel 
Lubricants Section, Service Branch, Technical Divi¬ 
sion, Office of Chief of Ordnance, Nov. 25, 1943. 

12. Hydraulic and Recoil Oils (Ninth Progress Report 

for the period from Sept. 24, 1943, to Apr. 11, 1944), 
M. R. Fenske, OSRD 3499, OEMsr-408, Service 
Projects AC-7, AC-8, and OD-61, Pennsylvania State 
College, Apr. 17, 1944. Div. 11-200-M6 


13. Hydraulic, Recoil and Special Oils (Tenth Progress 
Report), M. R. Fenske, OSRD 4492, OEMsr-408, 
Service Projects AC-7, AC-8, and OD-61, Pennsyl¬ 
vania State College, Dec. 12,1944. Div. 11-200-M7 

14. Hydraulic, Recoil and Special Oils, M. R. Fenske, 

OSRD 6643, OEMsr-408, Service Projects AC-7, 
AC-8, and others, Pennsylvania State College, Mar. 
25,1946. Div. 11-200-M8 

Chapter 2 

1. Removal of Dust from Air Supplied to Aircraft En¬ 
gines (Report to Jan. 31, 1943), T. H. Chilton and 
C. E. Lapple, OSRD 1178, OEMsr-506, Service Proj¬ 
ect NACA-1, E. I. duPont de Nemours and Co., Inc., 
Feb. 4, 1943. Div. 11-201.2-MI 

Chapter 3 

1. Protection of Aeroplanes from Gasoline Fires and 
Explosions (Report to Oct. 14, 1942), William R. 
Yant, OSRD 1019, OEMsr-425, Service Project NA- 
105, Mine Safety Appliances Co., Oct. 15, 1942. 

Div. 11-201.1-MI 

2. Elimination of Fire Hazards in Aircraft Through 

the Use of Inert Gases, H. W. Naulty, OSRD 1957, 
Service Project NA-105, Curtiss-Wright Corp., Oct. 
27,1943. Div. 11-201.1-M2 

3. The Physiological Effects of the Inhalation of Di- 

chlorodifluoromethane, Freon 12, upon Human Be¬ 
ings. Protection of Airplanes from Gasoline Fires 
and Explosions, Robert A. Kehoe, OSRD 3072, 
OEMsr-425, Service Project NA-105, University of 
Cincinnati, Jan. 4, 1944. Div. 11-201.1-M3 

4. The Use of Exhaust Gases to Inert the Vapor Space 
in Aircraft Fuel Tanks, C. C. Furnas, OSRD 3828, 
OEMsr-1244, Service Project NA-105, Curtiss- 
Wright Corp., June 26, 1944. Div. 11-201.1-M4 

Chapter 4 

1. Aerial Photographic Flash Powders (Report to Oct. 

15,1941), C. R. Hoover, NDCrc-92, OSRD 171, Serv¬ 
ice Project AC-29, Wesleyan University, Nov. 8, 
1941. Div. 11-202.3-MI 

2. The Development, of Flares Suitable for Underwater 
Use, C. R. Hoover, OSRD 435, OEMsr-158, Report 
196, Wesleyan University, Feb. 20, 1942. 

Div. 11-202.11-MI 


187 




188 


BIBLIOGRAPHY 


3. Aerial Photographic Flash Powders. Composition 
and Use, C. R. Hoover, OSRD 497, NDCrc-92, Report 
223, Wesleyan University, Feb. 15, 1942. 

Div. 11-202.3-M2 

4. The Flash Photography of Detonating Explosives, 
Explosives Research Laboratory, OSRD 1488, June 
3, 1943. 

5. Underwater Flares, G. Albert Hill and R. G. Clarke, 

OSRD 1522, OEMsr-321, Wesleyan University, June 
17, 1943. Div. 11-202.11-M2 

6. Improvement of Photoflash Bombs, G. Albert Hill 
and R. G. Clarke, OSRD 2010, OEMsr-321, Service 
Project AC-29, Wesleyan University, Nov. 13, 1943. 

Div. 11-202.2-MI 

7. Results of Tests on Modified M-U6 and M-60 Photo¬ 

flash Bombs, G. Albert Hill and R. G. Clarke, OSRD 
2095, OEMsr-321, Service Project AC-29, Wesleyan 
University, Dec. 6, 1943. Div. 11-202.2-M2 

8. Underwater Flares, G. Albert Hill and R. G. Clarke, 

OSRD 4030, OEMsr-321, Wesleyan University, Aug. 
15, 1944. Div. 11-202.11-M3 

9. Colored Flares, G. Albert Hill and R. G. Clarke, 

OSRD 4408, OEMsr-321, Wesleyan University, Nov. 
25, 1944. Div. 11-202.12-MI 

10. Colored Flares (Supplement to OSRD 4408), G. Al¬ 
bert Hill and R. G. Clarke, OSRD 4408A, OEMsr- 
321, Wesleyan University, Feb. 10, 1945. 

Div. 11-202.12-M2 

11. The Production of Photographic Flashes from Metal 
Powders, J. C. Cackett, AC 8090, Explosives Report 
408/45, Armament Research Department, Mar. 1945. 

12. Tests of Photoflash Bombs, G. Albert Hill and R. G. 
Clarke, OSRD 5457, OEMsr-321, Service Project 
AC-29, Wesleyan University, Aug. 18, 1945. 

Div. 11-202.2-M3 

13. Apparatus and Methods for the Study of Photoflash 
Bomb Explosions, G. Albert Hill, R. G. Clarke, and 
others, OSRD 6333, OEMsr-321, Service Project 
AC-29, Wesleyan University, Nov. 15, 1945. 

Div. 11-202.2-M4 


Chapter 5 

1. Means of Improving Inflation of Life Rafts at Low 

Temperatures, W. H. McAdams, G. C. Williams, and 
C. C. Neas, OSRD 3101, OEMsr-1169, Service Proj¬ 
ect NE-102, Massachusetts Institute of Technology, 
Jan. 11, 1944. Div. 11-203.1-MI 

2. Means of Improving Inflation of Life Rafts at Low 

Temperatures, W. H. McAdams, C. C. Neas, and G. 
C. Williams, OSRD 3525, OEMsr-1169, Service Proj¬ 
ect NE-102, Massachusetts Institute of Technology, 
Apr. 25, 1944. Div. 11-203.1-M2 


Chapter 6 

1. Advanced Positions Identification, J. Bertram Bates, 
OSRD 4691, OEMsr-1373, Service Project SOS-12, 
General Printing Corp., Feb. 14, 1945. 

Div. 11-203.21-MI 


Chapter 7 

1. Generation of Hydrogen for Barrage Balloons, R. C. 

Wilcox, OSRD 531, Service Project AC-39, Report 
228, Apr. 24, 1942. Div. 11-203.3-MI 

2. Preliminary Engineering Study of Chemical Proc¬ 
esses for the Manufacture of Sodium Borohydride, 
T. W. Stricklin, Jr., Informal Report under Contract 
OEMsr-953, Mar. 30, 1943. 

3. New Processes for Lithium Production (Progress 
Report for the period from Mar. 15 to Oct. 18,1943), 
OSRD 2089, OEMsr-930, Service Project SC-44, Na¬ 
tional Research Corp., Dec. 3, 1943. 

Div. 11-203.31-MI 

4. Design of Plant for Producing Sodium Hydride- 
Aluminum Mixture, H. G. Hyland and C. M. Hunter, 
OSRD 3053, OEMsr-928, Service Project SC-44, E. 
I. duPont de Nemours and Co., Inc., Dec. 29, 1943. 

Div. 11-203.3-M2 

5. Report of Test of Hydrogen Generators, Field Artil¬ 
lery Board, Fort Bragg, N. C., Jan. 10, 1944. 

6. Generator for the Use of Sodium Hydride-Aluminum 

Mixture for Field Generation of Hydrogen, H. A. 
Bond and J. J. McGovern, OSRD 3141, OEMsr-928, 
Service Project SC-44, E. I. duPont de Nemours and 
Co., Inc., Jan. 15, 1944. Div. 11-203.3-M3 

7. Sodium Hydride-Aluminum Mixtures for Field Gen¬ 

eration of Hydrogen, H. A. Bond and J. W. Dun¬ 
ning, OSRD 3142, OEMsr-928, Service Project SC- 
44, E. I. duPont de Nemours and Co., Inc., Jan. 15, 
1944. Div. 11-203.3-M4 

8. New Processes for Lithium Production (Progress 
Report for the period from Mar. 15 to Dec. 31,1943), 
OSRD 3758, OEMsr-930, Service Project SC-44, Na¬ 
tional Research Corp., June 8, 1944. 

Div. 11-203.31-M2 

9. Operational Suitability Test of Hydrogen Generator, 
Army Air Forces Board, Orlando, Fla., July 6, 1944. 


Chapter 8 

1. Sea Marking Devices, James A. MacLeod, OSRD 
4571, OEMsr-1206, Service Project NE-100, General 
Printing Ink Co., Jan. 9, 1945. Div. 11-203.22-MI 



BIBLIOGRAPHY 


189 


Chapter 9 

1. Mine Safety Appliances Company*s Self-Contained 
Oxygen Apparatus, Robert J. Benford, Thorne M. 
Carpenter, and others, NDCrc-69, Report 35, Har¬ 
vard University, June 2, 1941. Div. 11-203.4-MI 

2. The Technique for Testing Oxygen Masks, C. K. 
Drinker, T. M. Carpenter, and F. W. Maurer, OSRD 
117, July 31, 1941. 

3. An Account of the Construction and Efficiency of 

Mask L-12 for Oxygen Inhalation in Military Avia¬ 
tion, C. K. Drinker, OSRD 130, NDCrc-69, Service 
Project HM-1, Report 68, Harvard University, Aug. 
28, 1941. Div. 11-203.4-M2 

4. Examination of Three Masks Employed for Oxygen 
Inhalation in Military Aviation, C. K. Drinker, T. M. 
Carpenter, and F. W. Maurer, OSRD 164, Nov. 5, 
1941. 

5. The Construction of Mask L-12 for Oxygen Inhala¬ 
tion in Military Aviation, C. K. Drinker, T. M. Car¬ 
penter, and F. W. Maurer, OSRD 335, Jan. 1, 1942. 

6. Development of a Full-Face Oxygen Mask Incorpo¬ 
rating Ventilated Fog-Proof Lenses, Frank W. 
Maurer, OSRD 3164, OEMsr-320, Service Project 
AC-38, Harvard University, Jan. 20, 1944. 

Div. 11-203.4-M3 

7. Full-Face Oxygen Mask Incorporating Ventilated 

Fog-Proof Lenses, Frank W. Maurer, OSRD 4584, 
OEMsr-320, Service Project AC-38, Harvard Uni¬ 
versity, Jan. 18, 1945. Div. 11-203.4-M4 


Chapter 10 

1. Preliminary High-Altitude Spray Tests, H. 0. Huss, 
TDMR 329, CWS, December 1941. 

2. Evaporation of Falling Drops (Progress Report to 
Oct. 17, 1941), T. K. Sherwood and G. C. Williams, 
OEMsr-6, Service Project CWS-12, Massachusetts 
Institute of Technology, Dec. 6, 1941. 

Div. 11-203.524-MI 

3. Thickening of Vesicants, Duncan M. Maclnnes, 

OSRD 318, OEMsr-130, Service Project CWS-12, 
Report 155, Rockefeller Institute for Medical Re¬ 
search, Jan. 7, 1942. Div. 11-203.512-MI 

4. Thickening of HS, Donald Belcher and Duncan A. 
Maclnnes, OSRD 581, OEMsr-130, Service Project 
CWS-12, Report 249, Rockefeller Institute for Medi¬ 
cal Research, May 15, 1942. Div. 11-203.512-M2 

5. Thickening of HS-Ml Mixtures and a Photographic 
Study of the Impact of HS Drops on Cloth, Duncan 
A. Maclnnes, Donald Belcher, and Andrew Tait, 
OSRD 667, OEMsr-130, Service Projects CWS-12 
and NLB-36, Report 279, Rockefeller Institute for 
Medical Research, June 15,1942. Div. 11-203.512-M3 


6. Rheological Properties of Thickened Liquids (First 
Report, for the period from June 5, 1942 to Dec. 1, 

1942) , E. K. Carver and G. Broughton, OSRD 1113, 
OEMsr-538, Service Projects CWS-10, CWS-12, and 
others, Eastman Kodak Co., Dec. 7, 1942. 

Div. 11-203.512-M4 

7. Thickened Vesicants—Storage Stability and Other 
Properties of Vesicants and Thickened Vesicants, 
R. Macy, B. L. Harris, C. W. Huffman, TDMR 481, 
CWS, Dec. 12, 1942. 

8. Development of Vesicant Thickeners (Progress Re¬ 
port for the period from Dec. 9, 1942, to Jan. 2, 

1943) , M. M. Brubaker, OSRD 1185, OEMsr-743, 
Service Projects CWS-10, CWS-12, and CWS-21, 
E. I. duPont de Nemours and Co., Inc., Feb, 6, 1943. 

Div. 11-203.512-M5 

9. Thickened Vesicants—Feasibility of Rapid Prepara¬ 
tion of Thickened Levinstein HS in the Field, B. L. 
Harris, H. Barnard, and R. Macy, TDMR 572, CWS, 
Feb. 22, 1943. 

10. Stability of Liquid Vesicants, Duncan A. Maclnnes 
and Donald Belcher, OSRD 1346, OEMsr-130-D, 
Service Project CWS-12, Rockefeller Institute for 
Medical Research, Apr. 7,1943. Div. 11-203.512-M6 

11. Levinstein Mustard: Composition Purification, Sta¬ 
bilization, C. A. Rouiller, TDMR 612, CWS, Apr. 15, 
1943. 

12. Thickened Vesicants. Pilot Plant—Scale Thickening 
of Levinstein HS with a Methyl Methacrylate Poly¬ 
mer, J. W. Eastes, TDMR 633, CWS, Apr. 17, 1943. 

13. Fragmentation of Liquids (Progress Report to May 
1,1943), T. H. Chilton, R. L. Pigford, and J. B. Tepe, 
OSRD 1503, OEMsr-606, Service Projects CWS- 
10, CWS-12, and CWS-21, E. I. duPont de Nemours 
and Co., Inc., May 31,1943. Div. 11-203.512-M7 

14. Thickened Vesicants: Pilot Plant—Scale Thickening 
of Levinstein HS with Various Polymers, B. L. Har¬ 
ris, J. W. Eastes, H. Barnard, TDMR 673, CWS, 
June 14, 1943. 

15. Thickened Vesicants: The Rate of Solution of 
Polymers of Vinyl Acetate, Styrene and Methyl 
Methacrylate in Levinstein HS and in Thiodiglycol 
HS, J. W. Eastes, R. Macy, TDMR 696, CWS, July 
14, 1943. 

16. Thickened Vesicants: The Field Thickening of 
Levinstein H and Thiodiglycol H by Means of Con¬ 
centrated Solutions of Thickeners, J. W. Eastes, R. 
Macy, TDMR 703, CWS, July 21, 1943. 

17. Airplane Spray Tests of Thickened H Solutions 
(Newsprint and Asbestos Fibers, High Polymer 
Acetates, Plexiglas), Herbert Peters, H. O. Huss, 
TDMR 718, CWS, Aug. 14, 1943. 



190 


BIBLIOGRAPHY 


18. Rheological Measurements on Thickened Vesicants 

(Progress Report to Aug. 27, 1943), E. K. Carver 
and John R. Van Wazer, Jr.. OSRD 1893, OEMsr- 
538, Service Project CWS-12, Eastman Kodak Co., 
Oct. 5, 1943. Div. 11-203.512-M8 

19. Composition of Levinstein Mustard, Charles L. 
Thomas, OSRD 1978, OEMsr-844, Service Project 
CWS-4, Universal Oil Products Co., Oct. 29, 1943. 

Div. 11-203.511-M2 

20. Stabilization of Levinstein H in One-Ton Contain¬ 
ers and 55-Gallon Drums at Pine Bluff Arsenal, 
B. L. Harris, R. Macy, TDMR 763, CWS, Nov. 5, 

1943. 

21. Joint CWS-NDRC Report of Steam Distillation 
Process, H. C. Weber and W. H. McAdams, CWS 
Development Laboratory, Sept. 16, 1943. 

Div. 11-203.511-MI 

22. Purification of Levinstein Mustard by Crystal Frac¬ 
tionation, Louis S. Kassel and Curtis F. Gerald, 
OSRD 2003, OEMsr-844, Service Project CWS-4, 
Universal Oil Products Co., Nov. 9, 1943. 

Div. 11-203.511-M3 

23. [The] M-67 Modified for Improved Dispersion of H, 
J. R. Peer, G. Broughton, and C. K. Carver, OSRD 
2058, OEMsr-538, Service Project CWS-27, East¬ 
man Kodak Co., Nov. 20,1943. Div. 11-203.521-MI 

24. Spec. 196-131-207 — Coating, Phenolic, Protective, 
Heat Hardenable, Nov. 29, 1943. 

25. Memorandum on Airplane Vesicant Spray, T. K. 
Sherwood, OSRD 2093, Dec. 2, 1943. 

Div. 11-203.522-MI 

26. Part A. The Preparation of Thickened Levinstein 
H for Airplane Spray by Field Thickening Methods, 
J. W. Eastes, H. Peters, and H. O. Huss, TDMR 769, 
CWS, Dec. 7, 1943. 

27. Purification of Levinstein Mustard by Distillation 
with Pentane Vapor, Louis S. Kassel, Curtis F. 
Gerald, and Charles L. Thomas, OSRD 3047, 
OEMsr-844, Service Project CWS-4, Universal Oil 
Products Co., Dec. 29, 1943. Div. 11-203.511-M4 

28. Purification of Levinstein Mustard, W. E. Kuhn, G. 
B. Arnold, and L. E. Rudisch, OSRD 3217, OEMsr- 
897, Service Project CWS-4, The Texas Co., Feb. 5, 

1944. Div. 11-203.511-M5 

29. Purification of Crude Levinstein H, W. H. Mc¬ 

Adams, OSRD 3242, OEMsr-1017, Service Project 
CWS-4, Massachusetts Institute of Technology, Feb. 
11,1944. Div. 11-203.511-M6 

30. Development of Vesicant Thickeners, E. P. Czerwin, 
J. Harmon, and W. H. Wood, OSRD 3450, OEMsr- 
743, Service Project CWS-12, E. I. duPont de Ne¬ 
mours and Co., Inc., Apr. 6,1944. Div. 11-203.512-M9 


31. Drop Dispersion Measurements by Use of a Labora¬ 
tory Mortar, R. L. Pigford and T. H. Chilton, OSRD 
3542, OEMsr-606, Service Project CWS-12, E. I. du¬ 
Pont de Nemours and Co., Inc., Apr. 28, 1944. 

Div. 11-203.524-M2 

32. The Use of Thickened Vesicants in Chemical Shells, 
R. L. Pigford and T. H. Chilton, OSRD 3543, OEMsr- 
606, Service Project CWS-12, E. I. duPont de Ne¬ 
mours and Co., Inc., Apr. 28, 1944. 

Div. 11-203.512-M10 

33. Purification of Levinstein, H, S. W. Walker, J. H. 
Carpenter, and T. Q. Eliot, Memorandum Report 
Contract 5087-66, Chemical Warfare Development 
Laboratory at MIT, Part I, Appendix A-E, Part I, 
Appendix F-O, Part II, Part III, Appendix A-E, 
Part II, Appendix F-M, May 23, 1944. 

34. Thickened Vesicants: Thickening Purified H with 
Polymethyl Methacrylate (MM), J. W. Eastes, R. 
Macy, TDMR 868, CWS, July 17,1944. 

35. Thickened Vesicants: The Use of L Thickened with 
Methyl Methacrylate Polymer to Field Thickened 
Levinstein H, J. W. Eastes, R. Macy, TDMR 874, 
CWS, July 18, 1944. 

36. Modified Vacuum Distillation Process for Purifica¬ 
tion of Levinstein H, A. M. Reeves, TDMR 879, 
CWS, Aug. 22, 1944. 

37. Stabilization of Levinstein H. The Rate of Corro¬ 
sion of Steel Test Pieces by Levinstein H as Affected 
by the Ratio of Volume of Levinstein H to Area of 
Steel Surface, J. W. Eastes, R. Macy, TDMR 884, 
CWS, Aug. 26, 1944. 

38. Thickened Vesicants: The Molecular Weight of and 
Specifications for Poly Methyl Methacrylate (MM) 
Used for Thickening Vesicants, J. W. Eastes, TDMR 
869, CWS, Aug. 31, 1944. 

39. Stabilization of Levinstein H. The Corrosion of 
Steel Test Pieces by Various Types of Unstabilized 
and Stabilized Mustard, and a Discussion of Storage 
Stability of Mustard in Terms of Current Theories 
of Corrosion and Chemical Properties of the H Mole¬ 
cule, J. W. Eastes, R. Macy, TDMR 890, CWS, Sept. 
20, 1944. 

40. Thickening Levinstein with Methacrylate Polymer, 
CWS Directive 262, Amendment, Oct. 12, 1944. 

41. Properties of Thickened Liquids, R. L. Pigford, 

OSRD 4284, OEMsr-606, Service Projects CWS-10, 
CWS-12, and others, E. I. duPont de Nemours and 
Co., Inc., Oct. 25, 1944. Div. 11-203.512-Mil 

42. Thickener, Persistent Agent, VV, Specification 196- 
21-37 (Canceled Mar. 28, 1945), Nov. 18, 1944. 

43. Stabilization of Levinstein H. The Storage Stability 
of Steam-Distilled H in Uncoated M7U Bombs at 
65 C, J. W. Eastes, R. Macy, TDMR 937, CWS, Nov. 
24, 1944. 





BIBLIOGRAPHY 


191 


44. Rate of Evaporation of H from HS (Levinstein) 
Containing Small Percentages of WP (First Re¬ 
port), 0. Johnson and H. J. Fish, Technical Minute 
79, Suffield Experimental Station, Suffield, Alberta, 
Canada, Nov. 24,1944. 

45. Evaporation of H from HS (Levinstein) Containing 
Small Percentages of WP, 0. Johnson, Technical 
Minute 80, Suffield Experimental Station, Suffield, 
Alberta, Canada, Dec. 10, 1944. 

46. Report of the Joint Chemical Spray Project Sub¬ 
committee of the U. S. Chemical Warfare Commit¬ 
tee, Dec. 31, 1944. 

47. Vaporization Characteristics of H and HP, A. W. 

Larchar, OSRD 4634, OEMsr-743, Service Project 
CWS-4, E. I. duPont de Nemours and Co., Inc., Jan. 
27,1945. Div. 11-203.523-MI 

48. Vacuum Distillation of Levinstein H. Pilot Plant 
Study, W. R. Wheeler, W. Marcy, A. E. Perry, and 
W. R. Wilson, TDMR 985, CWS, Mar. 17, 1945. 

49. Vacuum Distillation of Levinstein H. Pilot Plant 
Study, W. R. Wheeler, W. Marcy, A. E. Perry, and 
W. R. Wilson, Report on Process, TDMR 985, Edge- 
wood Arsenal, Mar. 17, 1945. 

50. Methyl Methacrylate Polymer, Specification 196-21- 
39, Mar. 22, 1945. 

51. Vaporization Characteristics of H and HP, A. J. Hill, 

Jr., OSRD 5164, OEMsr-743, Service Project CWS- 
4, E. I. duPont de Nemours and Co., Inc., May 31, 
1945. Div. 11-203.523-M2 

52. Vesicant Studies, Duncan A. Maclnnes and Donald 
Belcher, OSRD 5391, OEMsr-130, Service Project 
CWS-12, CWS-4, and NLB-36, Rockefeller Institute 
for Medical Research, Aug. 10, 1945. 

Div. 11-203.512-M13 

53. Polymethyl Methacrylate as a Thickener for H, J. C. 
Thomas and W. H. Wood, OSRD 5347, OEMsr-743, 
Service Project CWS-12, E. I. duPont de Nemours 
and Co., Inc., July 18,1945. Div. 11-203.512-M12 

54. Stability of Thickened Levinstein H Solutions, E. P. 
Czerwin and W. H. Wood, OSRD 5426, OEMsr-743, 
Service Project CWS-12, E. I. duPont de Nemours 
and Co., Inc., Aug. 17, 1945. Div. 11-203.512-M14 

55. Storage Stability of Mustard Gas, W. H. Wood, 

OSRD 5450, OEMsr-743, Service Project CWS-12, 
E. I. duPont de Nemours and Co., Inc., Aug. 17, 
1945. Div. 11-203.51-MI 

56. Neutralization of the Effects of Iron Compounds in 

Thickened Levinstein H, J. Harmon and W. H. Wood, 
OSRD 5456, OEMsr-743, Service Project CWS-12, 
E. I. duPont de Nemours and Co., Inc., Aug. 22, 
1945. Div. 11-203.512-M15 

57. H Purification Plant, 1944, Design HD-W (Rocky 
Mt. Arsenal), CWS Operating Directive, 1945. 


Chapter 11 

1. “The Aerodynamics of a Spinning Shell,” R. H. 
Fowler, E. G. Gallop, C. N. H. Lock, and H. W. 
Richmond, Philosophical Transactions of the Royal 
Society (London), A, 1921, Vol. 221, pp. 295-388. 

2. 4‘2-in. Chemical Mortar, A. E. Nissen, A. A. Gandy, 
and A. L. Hodges, EAMD 26, Mar. 17, 1927. 

3. “The Role of Model Experiments in Projectile De¬ 
sign,” R. H. Kent, Mechanical Engineering , 1932, 
Vol. 54, pp. 641-6. 

4. 4-2-in. Chemical Mortar Empty Complete Round for 
HS and CG Fillings, J. R. Burns, EATR 204, CWS, 
Edgewood Arsenal, Feb. 19, 1936. 

5. Stability of Liquid-Filled Shell, E. A. Milne, E.B.D. 
Report No. 6, B-3997, September 1940; cf. also “The 
Oscillations of a Rotating Ellipsoidal Shell Con¬ 
taining Fluid,” S. S. Hough, Philosophical Transac¬ 
tions of The Royal Society (London), A, 1895, Vol. 
186, pp. 469-506. 

6. Some Effects of Rotation of Liquid-Filled Shell, B. 
A. Griffith and C. H. B. Priestly, Suffield Report 6, 
Feb. 19, 1942. 

7. Stability and Resistance Firings, Proof Manual 15- 
10, Ordnance Department, Aug. 7,1943. 

8. The Use of Thickened Vesicants in Chemical Shells. 
A Literature Survey, R. L. Pigford and T. H. Chil¬ 
ton, OEMsr-606, Project TX-W-2, E. I. duPont de 
Nemours and Co., Inc., Jan. 12, 1944. 

Div. 11-203.6-MI 

9. Motion of a Projectile with Small or Slowly-Chang¬ 
ing Yaw, J. L. Kelley and E. J. McShane, Ballistic 
Research Laboratory Report 446, Aberdeen Proving 
Ground, Aberdeen, Md., Jan. 29, 1944. 

10. Vaneless 4‘2-in. Chemical Mortar Shell E-51R3, A. 
R. T. Denues, Mortar Section Letter Report 20-1944, 
CWS Technical Command, Mar. 20, 1944. 

11. An Elementary Treatment of the Motion of a Spin¬ 
ning Projectile About its Center of Gravity, R. H. 
Kent and E. J. McShane, Ballistic Research Labora¬ 
tory Report 459, Aberdeen Proving Ground, Aber¬ 
deen, Md., Apr. 11, 1944. 

12. The Instability of Liquid-Filled Shell, W. F. Cope, 
The National Physical Laboratory, Apr. 23, 1944. 

13. A Method of Measuring Stability of Projectiles Dur¬ 
ing Flight, A. Pitt, University of Toronto, May 20, 
1944. 

14. Stability of Shell. H.M2. 4-2 CM: Orienting Study 
of Fraction Filled — Preliminary Report, A. R. T. 
Denues, Mortar Section Letter Report 83-1944, May 
31, 1944. 

15. Ballistic Stability of Liquid-Filled Shell, A. Pitt, 
University of Toronto, Dec. 5, 1944. 



192 


BIBLIOGRAPHY 


16. Outline of 4.2-in. Chemical Mortar Development, 
A. R. T. Denues and C. T. Mitchell, Monograph Re¬ 
port, CWS, 1945. 

17. Exterior Ballistics of Liquid-Filled Shell, R. L. Pig- 

ford, OSRD 6441, OEMsr-1395, Service Project 
CWS-31, E. I. duPont de Nemours and Co., Inc., Dec. 
29, 1945. Div. 11-203.6-M2 

Chapter 12 

1. Test of Portable Hydrogen Generator, E5 (A Memo¬ 
randum Report), L. W. Russum and D. B. Salmon, 
TDMR 987, CWS, Feb. 11, 1945. 

2. Generator, Hydrogen, High Pressure, Portable, E5, 
No. 1776, Infantry Board, Fort Benning, Ga., Mar. 
3, 1945. 

3. Test of Generator, Hydrogen, High Pressure, Port¬ 
able, E5, No. 237, Airborne Board, Headquarters 
Airborne Center, Camp Mackall, N. C., Mar. 23, 
1945. 

4. Field Test of E5 Portable High Pressure Hydrogen 
Generator, Project 620, CW Board, Edgewood Ar¬ 
senal, Md., Apr. 14, 1945. 

5. Generator, Hydrogen, High Pressure, Portable E5, 
No. 393, Marine Equipment Board, Marine Bar¬ 
racks, Quantico, Va., Apr. 30, 1945. 

6. Generator, Hydrogen, High Pressure Portable, 
E5R1, Technical Manual TM3-374, War Depart¬ 
ment, July 7, 1945. 

7. Development of Portable Cordite Operated Gas Gen¬ 
erator for Pressurizing M2-A2 Flame Throwers, A. 

S. Collins and A. A. Nellis, Massachusetts Institute 
of Technology, July 12,1945. Div. 11-302.13-M2 

8. Development of a Portable Front Line Gas Genera¬ 
tor for Pressurizing Portable Flame Throwers, A. 
S. Collins, W. H. McAdams, and others, OSRD 6356, 
OEMsr-1169, Service Project CWS-10, Massachu¬ 
setts Institute of Technology, Nov. 26, 1945. 

Div. 11-302.13-M3 


Chapter 13 

1. Fundamental Factors in the Design of Protective 

Respiratory Equipment, Leslie Silverman, Robert C. 
Lee, and others, OSRD 1222, OEMsr-306, Service 
Projects CWS-7 and CWS-16, Harvard University, 
Mar. 4, 1943. Div. 11-204.2-MI 

2. Fundamental Factors in the Design of Respiratory 
Equipment. The Characteristics of Inspiratory and 
Expiratory Values (Progress Report to Aug. 1, 
1943), Leslie Silverman, Robert C. Lee, and George 
Lee, OSRD 1864, OEMsr-306, Service Projects CWS- 
16 and CWS-1, Harvard University, Oct. 1, 1943. 

Div. 11-204.2-M2 


3. Fundamental Factors in the Design of Protective 

Respiratory Equipment. Inspiratory Resistances of 
US Army Chemical Warfare Service Gas Masks 
With Static and Dynamic Air Flow, Leslie Silver- 
man and Robert C. Lee, OSRD 3526, OEMsr-306, 
Service Project CWS-7, Harvard University, Apr. 
25, 1944. Div. 11-204.2-M3 

4. Fundamental Factors in the Design of Protective 

Respiratory Equipment. End Point Breathing Rate 
Studies, OSRD 4229, OEMsr-306, Harvard Uni¬ 
versity, Oct. 9,1944. Div. 11-204.2-M4 

5. Fundamental Factors in the Design of Protective 
Respiratory Equipment. A Portable Instrument for 
Measuring Respiratory Air Flows Under Field Con¬ 
ditions, Leslie Silverman, Theodore Plotkin, and 
others, OSRD 5338, OEMsr-306, Harvard Univer¬ 
sity, Carnegie Institution of Washington, and Mass¬ 
achusetts Institute of Technology, July 17, 1945. 

Div. 11-204.2-M5 

6. Fundamental Factors in the Design of Protective 

Respiratory Equipment. A Study and an Evaluation 
of Inspiratory and Expiratory Resistances for Pro¬ 
tective Respiratory Equipment, Leslie Silverman, 
George Lee, and others, OSRD 5339, OEMsr-306, 
Service Project CWS-7, Harvard University, July 
17, 1945. Div. 11-204.2-M6 

7. Fundamental Factors in the Design of Protective 
Respiratory Equipment. Measurements of Inspira¬ 
tory Air Flow on Soldiers Performing Various Field 
Operations, Leslie Silverman, Theodore Plotkin, and 
George Lee, OSRD 5496, OEMsr-306, Service Proj¬ 
ect CWS-7, Harvard University, Aug. 27, 1945. 

Div. 11-204.2-M7 

8. Fundamental Factors in the Design of Protective 

Respiratory Equipment. Inspiratory and Expira¬ 
tory Air Flow Measurements on Human Subjects 
with and without Resistance at Several Work Rates, 
Leslie Silverman, George Lee, and others, OSRD 
5732, OEMsr-306, Service Project CWS-7, Harvard 
University, Sept. 18, 1945. Div. 11-204.2-M8 


Chapter 14 

1. Report on Pro-Knock Materials, Albert L. Henne, 
OSRD 76, Mar. 3, 1941. 

2. Pro-Knock (Final Report to Aug. 4, 1941), Thomas 

Midgley, Jr., and Albert L. Henne, NDCrc-3, Serv¬ 
ice Projects AC-2 and CWS-5, Ethyl Gasoline Corp., 
Sept. 5, 1941. Div. 11-205.2-MI 

3. Effect of Strong Pro-Knock Materials in Gasoline 

Similar to That Reportedly Used in German Air¬ 
craft, Thomas Midgley, Jr., OSRD 183, Service Proj¬ 
ects AC-2 and CWS-5, Ethyl Gasoline Corp., Dec. 1, 
1941. Div. 11-205.2-M2 



BIBLIOGRAPHY 


193 


4. Pro-Knock Materials, Thomas Midgley, Jr., OSRD 

392, Service Projects AC-2 and CWS-5, Ethyl Gaso¬ 
line Corp., Feb. 12, 1942. Div. 11-205.2-M3 

5. Pro-Knock, OSRD 668, Ethyl Gasoline Corp., May 
26, 1942. 

6. Pro-Knock (Supplement to the Final Report of May 
26, 1942), OSRD 1281, OEMsr-231, Service Project 
AC-2, Ethyl Gasoline Corp., Mar. 20, 1943. 

Div. 11-205.2-M4 

7. Chemical Treatment of Oils. Sabotage of Gasoline 
(Progress Report for period from Oct. 1, 1940, to 
Mar. 7, 1941), OSRD 81, Service Projects AC-2 and 
CWS-5, Monsanto Chemical Co., Mar. 7, 1941. 

Div. 11-205.1-MI 

8. Chemical Treatment of Oils (Sabotage of Gasoline), 
OSRD 92, Monsanto Chemical Co., Apr. 16, 1941. 

9. Preliminary Study of Methods of Sabotage of Lubri¬ 
cating Oils, H. B. Weiser, OSRD 471, OEMsr-189, 
Service Project AC-2, Rice Institute, Mar. 28, 1942. 

Div. 11-205.1-M2 

10. Sabotaging Engines by Additions to the Lubricating 
Oil (Final Report to Jan. 15, 1943), T. A. Boyd, 
OSRD 1252, OEMsr-428, Service Project AC-2, 
Ethyl Gasoline Corp., Mar. 11, 1943. 

Div. 11-205.1-M3 


Chapter 15 

1. Removal of Salts from Sea Water (Report to June 
15, 1941), A. M. Buswell, NDCrc-50, Service Project 
NLB-5, University of Illinois, June 15, 1941. 

Div. 11-203.71-MI 

2. Desalting of Sea Water, OSRD 968, Resinous Prod¬ 
ucts Co., Oct. 19, 1942. 

3. Hand-Operated Vapor Compression Still for Produc¬ 

tion of Potable Water from Sea Water, T. L. 
Wheeler and Allen Latham, Jr., OSRD 3197, OEMsr- 
1047, Service Project NS-168, Arthur D. Little, Inc., 
Jan. 29, 1944. Div. 11-203.71-M2 

4. Solar Distiller for Life Rafts, Maria Telkes, OSRD 
5225, OEMsr-1164, Service Project NS-168, Massa¬ 
chusetts Institute of Technology, June 19, 1945. 

Div. 11-203.71-M3 


Chaper 16 

1. “Microbiological Anaerobic Corrosion,” A. F. Had¬ 
ley, Oil and Gas Journal, 1939, Vol. 38, pp. 92-94. 

2. Paint Removers, J. C. Elgin, Report 11, Princeton 

University, Feb. 20, 1941. Div. 11-206.3-MI 

3. Protective Coatings for Ship Bottoms, NDCrc-42, 
Problem 27, Bakelite Corp., Mar. 31, 1941. 

Div. 11-206.11-MI 


4. Protective Coatings for Naval Aircraft, NDCrc-42, 
Bakelite Corp., Mar. 31, 1941. Div. 11-206.2-MI 

5. Commercial Paint Removers, J. C. Elgin, NDCrc- 
29, Report 20, Princeton University, Apr. 2, 1941. 

Div. 11-206.3-M2 

6. Investigation of Paint Removers (Report to Oct. 31, 
1941), J. C. Elgin, NDCrc-29, OSRD 279, Service 
Project NL-B2, Princeton University, Dec. 9, 1941. 

Div. 11-206.3-M3 

7. Protective Coatings for Ship Bottoms (Report 159), 

A. J. Weith and V. H. Turkington, OSRD 324, 
OEMsr-52, Service Project NL-B4, Bakelite Corp., 
Jan. 14,1942. Div. 11-206.11-M2 

8. Protective Coatings for Naval Aircraft, A. J. Weith 
and V. H. Turkington, OSRD 368, OEMsr-211, Serv¬ 
ice Project NL-B4, Bakelite Corp., Feb. 7, 1942. 

Div. 11-206.2-M2 

9. Protective Coatings for Ship Bottoms and Naval 
Aircraft (Report to Jan. 15, 1942), A. J. Weith and 
V. H. Turkington, OSRD 413, OEMsr-211, Service 
Project NL-B4, Bakelite Corp., Feb. 26,1942. 

Div. 11-206-MI 

10. Protective Coatings, A. J. Weith and V. H. Turking¬ 
ton, OSRD 651, OEMsr-211, Service Projects NL- 
B2 and NL-B4, Bakelite Corp., Apr. 30, 1942. 

Div. 11-206-M2 

11. Protective Coatings for Ship Bottoms, A. J. Weith 
and V. H. Turkington, OSRD 881, OEMsr-211, Serv¬ 
ice Project NL-B4, Bakelite Corp., Aug. 25, 1942. 

Div. 11-206.11-M4 

12. Annotated Bibliography and Subject Index on Ship 
Bottom Fouling Organisms and Antifouling Re¬ 
search, Part I, Annotated bibliography. Part II, Sub¬ 
ject index. Part III, Summaries, George L. Clark, 
OSRD 1006, OEMsr-204, Service Project NL-B4, 
Harvard University, Sept. 15, 1942. 

Div. 11-206.11-M5 

13. Protective Coatings for Ship Bottoms (Progress Re¬ 
port to Dec. 1,1942), A. J. Weith and V. H. Turking¬ 
ton, OSRD 1174, OEMsr-211, Service Project NL- 
B4, Bakelite Corp., Feb. 3,1943. Div. 11-206.11-M6 

14. Methods for Cleaning Ship Bottoms, OSRD 1310, 

OEMsr-446, Service Project NL-B4, Bakelite Corp., 
Apr. 2, 1943. Div. 11-206.12-MI 

15. Fire Retardant Paints for Navy Ships, OSRD 1407, 

OEMsr-211, Service Project NS-129, Bakelite Corp., 
May 11, 1943. Div. 11-206.6-Ml 

16. Protective Coatings for Magnesium and Its Alloys 

(Progress Report to Apr. 30, 1943), OSRD 1462, 
OEMsr-211, Service Project NA-122, Bakelite Corp., 
May 28, 1943. Div. 11-206.5-MI 




194 


BIBLIOGRAPHY 


17. Protective Coatings for Ship Bottoms, OSRD 1838, 
OEMsr-211, Bakelite Corp., Sept. 9, 1943. 

Div. 11-206.11-M7 

18. Protective Coatings for Magnesium Alloys, OSRD 

2094, OEMsr-211, Service Project NA-122, Bakelite 
Corp., Dec. 6, 1943. Div. 11-206.5-M2 

19. Methods of Studying Corrosion and Blistering Ten¬ 

dencies of Underwater Coatings, OSRD 3066, 
OEMsr-211, Service Project NL-B4, Bakelite Corp., 
Jan. 3, 1944. Div. 11-206.4-MI 

20. Effects of Atmospheric Exposure on Paints Previ¬ 
ously Submerged in the Sea, OSRD 3904, OEMsr- 
211, Service Project NL-B4, Bakelite Corp., July 17, 

1944. Div. 11-206.11-M9 

21. Paint Destruction and Metal Corrosion, Selman A. 

Waksman and Robert L. Starkey, OSRD 4402, 
OEMsr-1259, Service Project NS-235, Rutgers Uni¬ 
versity, Nov. 30, 1944. Div. 11-206.4-M2 

22. Paint Destruction and Metal Corrosion. Zoological 

Aspects, Thurlow C. Nelson and E. R. Kodet, OSRD 
4512, OEMsr-1259, Service Project NS-235, Rutgers 
University, Dec. 27, 1944. Div. 11-206.41-MI 

23. The Value of Electrical Resistance in Studying the 
Protective Behavior of Organic Coatings on Mild 
Steel Immersed in Sea Water, OSRD 4847, OEMsr- 
211, Service Project NL-B4, Bakelite Corp., Mar. 23, 

1945. Div. 11-206-M3 

24. Interaction of Antifouling Paints and Steel, Alfred 

C. Redfield, OSRD 5053, Woods Hole Oceanographic 
Institution, May 11, 1945. Div. 11-206-M4 

25. Microbiological and Zoological Aspects of Paint De¬ 

struction and Metal Corrosion, Robert L. Starkey 
and John D. Schenone, OSRD 5665, OEMsr-1259, 
Service Project NS-235, Rutgers University, Sept. 
12, 1945. Div. 11-206.41-M2 

26. Studies of Anticorrosive and Antifouling Coating 
Systems for Ship Bottoms, OSRD 6649, OEMsr-211, 
Service Project NL-B4, Bakelite Corp., Apr. 5, 1946. 

Div. 11-206.11-Mil 

Chapter 17 

1. Corrosion Resistant Coatings for Chemical Muni¬ 

tions, Neil Thurman and Paul Robinson, OSRD 
1520, OEMsr-796, Service Projects CWS-13 and NO- 
126, E. I. duPont de Nemours and Co., Inc., June 17, 
1943. Div. 11-206.7-MI 

2. Linings for Fuel and Lubricant Containers, O. W. 
Tissari, OSRD 4762, OEMsr-796, NDCrc-711, Serv¬ 
ice Projects QMC-28 and AN-13, E. I. duPont de 
Nemours and Co., Inc., Mar. 3, 1945. 

Div. 11-206.8-M2 


3. The Cox Marine Electrocoating Process, O. W. Tis¬ 

sari, OSRD 4862, OEMsr-1223, Service Project 
QMC-28, Comstock and Wescott Co., Inc., Mar. 27, 
1945. Div. 11-206.8-M3 

4. Sealing of Navy Primers and Fuzes, W. F. Single- 

ton and W. C. Johnson, OSRD 6440, OEMsr-796, 
Service Project NO-288, E. I. duPont de Nemours 
and Co., Inc., Dec. 29, 1945. Div. 11-206.7-M2 


Chapter 18 

1. Methods for the Purification of Water After Its 
Transportation and Storage in Cans, Drums and 
Tanks That Have Been Employed as Containers for 
Leaded Gasoline, Robert A. Kehoe and J. Cholak, 
OSRD 1139, OEMsr-341, Service Project CE-19, 
University of Cincinnati, Dec. 9, 1942. 

Div. 11-203.72-MI 


Chapter 19 

1. Investigation of Methods of Producing Magnesium 
Fluoride for the Filming of Lenses, Frank C. Math¬ 
ers, OSRD 5449, OEMsr-1194, Service Project NO- 
189, University of Indiana, Aug. 17, 1945. 

Div. 11-206.51-MI 


Chapter 20 

1. Use of Substitute Materials in the Manufacture of 
Cork Plugs (Report to Nov. 1, 1941), Earl Stafford, 
OSRD 178, OEMsr-82, Service Project NOB-37, Ar¬ 
thur D. Little, Inc., Nov. 14,1941. Div. 11-209.1-Ml 


Chapter 21 

1. Studies and Investigation in Connection with the 
Possibility of Increasing the Capacity of Lead Stor¬ 
age Batteries by Modification of the Negative Plate, 
F. R. Bichowsky, OSRD 1926, OEMsr-565, Service 
Project NS-110, Catholic University, Oct. 16, 1943. 

Div. 11-209.2-MI 


Chapter 22 

1. Confining and Collecting Petroleum Products from 

Spills or Leaks to Waterways, W. B. Hart, OSRD 
916, Service Project NS-103, Atlantic Refining Co., 
Sept. 15, 1942. Div. 11-207.1-MI 

2. The Removal of Oil from Harbor Waters by Means 

of Chemically Treated Sand (Final Report to Nov. 
30, 1942), Morrough P. O’Brien, OSRD 1120, 
OEMsr-672, Service Project NS-103, University of 
California, Jan. 12, 1943. Div. 11-207.1-M2 




BIBLIOGRAPHY 


195 


Chapter 23 

1. Production of Ammonia from Urine, R. C. Wilcox, 
OSRD 1724, OEMsr-820, Service Project China-1, 
Harvard University, Aug. 20,1943. Div. 11-209.3-MI 

2. Biological Nitrification of Urine , G. M. Fair and 
C. E. Renn, OSRD 3462, OEMsr-820, Service Project 
China-1, Harvard University, Apr. 12, 1944. 

Div. 11-209.3-M2 

Chapter 24 

1. Preliminary Report of Test of Blast Mats T2 and 
T3 for Mobile Artillery , Tank Destroyer Board, 
Camp Hood, Texas, Aug. 16, 1944. 

2. Suppression of Dust Around Artillery Emplace¬ 
ments. Chemical Treatment of Ground, L. B. Ryon, 
OSRD 4540, OEMsr-1271, Service Project OD-154, 

Rice Institute, Jan. 4, 1945. Div. 11-207.2-MI 

# 

3. Suppression of Dust Around Artillery Emplace¬ 
ments. Blast Mats, L. B. Ryon, OSRD 5308, OEMsr- 
1271, Service Project OD-154, Rice Institute, July 2, 

1945. Div. 11-207.2-M2 

Chapter 25 

1. Stability and Concentration of Hydrogen Peroxide, 
Frederick G. Keyes, W. C. Schumb, and D. B. 
Broughton, OSRD 5385, OEMsr-1453, Massachu¬ 
setts Institute of Technology, Aug. 1, 1945. 

Div. 11-102.221-M3 

2. Hydrogen Peroxide, H. S. Gardner and T. K. Sher¬ 
wood, OSRD 5448, OEMsr-1453, Massachusetts In¬ 
stitute of Technology, Aug. 17, 1945. 

Div. 11-102.221-M4 

3. The Preparation of Hydrogen Peroxide Through 
the Cyclic Reduction and Oxidation of 2-Ethylan- 
thraquinone, Harry Schultz, James Carnahan, and 
Homer Adkins, OSRD 6087, Nov. 20, 1945. 

4. Laboratory Study of the Possibilities of Commercial 
Synthesis of Hydrogen Peroxide by Electrical and 
Photochemical Methods, W. H. Rodebush, C. R. 
Keizer, and others, OSRD 6644, OEMsr-1452, Uni¬ 
versity of Illinois, Mar. 25,1946. Div. 11-102.221-M5 

Chapter 26 

1. Shoes, Improvement of (Final Report for the period 
from Dec. 15, 1943, to Jan. 31, 1946), Ernest D. 
Wilson, Contract 44-109 qm-305, Service Project 
QMC-7, Worcester Polytechnic Institute, February, 

1946. Div. 11-208.34-MI 

Chapter 27 

1. The Preservation of Shoe Sewing Thread, Robert 
M. Lollar, OSRD 3069, OEMsr-718, Service Project 
QMC-17, University of Cincinnati, Jan. 3, 1944. 

Div. 11-206.9-MI 


2. The Influence of Oils on Shoe Leathers. Behavior 
of Oil-Treated Leather at Cold and Hot Tempera¬ 
tures, William C. Roddy and Domingo B. Gapuz, 
OSRD 3117, OEMsr-718, Service Project QMC-17, 
University of Cincinnati, Jan. 13, 1944. 

Div. 11-206.9-M2 

3. Sterilization of Used Army Shoes, Hoke S. Greene, 
OSRD 3118, OEMsr-718, Service Project QMC-17, 
University of Cincinnati, Jan. 13, 1944. 

Div. 11-206.9-M3 

4. Mold Resistant Treatments for Leathers, Robert M. 
Lollar, OSRD 3119, OEMsr-718, Service Project 
QMC-17, University of Cincinnati, Jan. 13, 1944. 

Div. 11-206.9-M4 

5. Preservatives in Army Dubbings, Hoke S. Greene 

and Robert M. Lollar, OSRD 3120, OEMsr-718, Serv¬ 
ice Project QMC-17, University of Cincinnati, Jan. 
13,1944. Div. 11-206.9-M5 

6. Improvement of Leather (Final Report for the pe¬ 

riod from Sept. 10, 1943, to Sept. 1, 1945), Fred 
O’Flaherty, Contract W44-109 qm-305, Service Proj¬ 
ect QMC-17, University of Cincinnati, September 
1945. Div. 11-206.9-M6 

Chapter 28 

1. Deleading of Gasoline (Final Report for the period 
from Nov. 5,1943, to June 30,1945), M. S. Kharasch, 
Contract W44-109 qm-305, Service Project QMC- 
19-A, University of Chicago, July 1945. 

Div. 11-208.41-M2 

Chapter 30 

1. Insects and Other Animals of Interest to the Quar¬ 
termaster Corps, Charles H. Blake and Henry D. 
Russell, OSRD 2091, OEMsr-888, Service Project 
QMC-22, Massachusetts Institute of Technology, 
September 1943. Div. 11-208.31-MI 

Chapter 31 

1. Troop Feeding Programs. A Survey of Rationing 
and Subsistence in the United States Army, 1755 to 
19UO, Samuel C. Prescott, OEMsr-929, Service Proj¬ 
ect QMC-23, Massachusetts Institute of Technology, 
March 1944. Div. 11-208.32-MI 

Chapter 32 

1. Western Hemisphere Bamboos as Substitutes for 
Oriental Bamboos for the Manufacture of Ski Pole 
Shafts (Final Report for the period from Apr. 15, 
1943, to May 31, 1944), F. A. McClure, OEMsr-1014, 
Service Project QMC-24, Smithsonian Institution, 
June 1944. Div. 11-208.33-MI 





196 


BIBLIOGRAPHY 


Chapter 33 

1. Solid Fuels for Heating Combat Rations (Sum¬ 
mary Report for the period from Aug. 9, 1943, to 
Feb. 29, 1944), Charles Paul McClelland and Robert 
Hayward Nimmo, Service Project QMC-26, Mellon 
Institute of Industrial Research, March 1944. 

Div. 11-208.42-MI 

Chapter 34 

1. Literature Search on Carbonaceous Fuels for Heat¬ 
ing Combat Rations (Summary Report for the pe¬ 
riod from Oct. 10 to Dec. 1, 1944), Robert Hayward 
Nimmo and Carol Lee Sittler, OEMsr-1055, Service 
Project QMC-26, Mellon Institute of Industrial Re¬ 
search, December 1944. Div. 11-208.42-M2 

Chapter 36 

1. Coatings, Organic (Final Report for the period from 
Oct. 15, 1943, to July 31, 1944), W. T. Pearce, 
OEMsr-1055, Service Project QMC-31, Temple Uni¬ 
versity, July 1944. Div. 11-206.8-MI 

Chapter 37 

1. Coated Fabrics and Thin Films (Report for the pe¬ 
riod from October 1943 to January 1946), Paul M. 
Doty, Turner Alfrey, and others, Contract W44-109 
qm-305, Service Project QMC-36, Brooklyn Poly¬ 
technic Institute, Feb. 1, 1946. Div. 11-208.12-M2 

Chapter 38 

1. Wear Resistance of Apparel Textiles (Final Report 
for the period from Feb. 1, 1944, to May 1, 1945), 
E. R. Schwarz, W. J. Hamburger, and others, 
OEMsr-1055, Service Project QMC-33, Massachu¬ 
setts Institute of Technology and Fabric Research 
Laboratories, Inc., May 1945. Div. 11-208.11-MI 

Chapter 39 

1. Shrinkproofing of Wool Knitted Items and Fabrics, 
Vol. 1 (Final Report for the period from Mar. 1, 
1944, through Dec. 31,1944), Arthur L. Smith, Lydia 
R. Hornstein, and others, OEMsr-1055, Service 
Project QMC-34, National Bureau of Standards, 
January 1945. Div. 11-208.13-MI 

Chapter 40 

1. Packaging with Plastics (Final Report for the pe¬ 
riod from May 1 to Oct. 31, 1945), Harry F. Lewis, 
T. A. Howells, and Otto Kress, Contract W44-109 
qm-305, Service Project QMC-44, Institute of Paper 
Chemistry, November 1945. Div. 11-206.8-M4 


Chapter 41 

1. Storage of Chlorinated Lime, Dayton E. Garritt, 

CQP Miscellaneous Project 1, Rhode Island State 
College. Div. 11-203.81-MI 

2. Storage of Chlorinated Lime, Jacob Katz and W. 

George Parks, CQP Miscellaneous Project 3, Rhode 
Island State College. Div. 11-203.81-M2 


Additional References 

1. Improvement of Vesicants, Studies of HP, E. K. El- 
lingboe and C. W. Todd, OSRD 6622, OEMsr-743, 
Service Project CWS-4, E. I. duPont de Nemours 
and Co., Inc., Feb. 25, 1946. Div. 11-203.512-M16 

2. Vesicant Studies, Vesicant Thickeners, Mustard 
Compositions Having Accelerated Evaporation 
Rates, J. E. Kirby, OSRD 6623, OEMsr-743, Service 
Projects CWS-12 and CWS-4, E. I. duPont de Ne¬ 
mours and Co., Inc., Feb. 25, 1946. 

Div. 11-203.512-M17 

3. Instantaneous Penetration Measurements under 

Conditions Approximating Human Respiration (Re¬ 
port to Oct. 1, 1943), W. K. Lewis and F. A. Wolff, 
OSRD 1866, OEMsr-347, Service Projects CWS-1 
and CWS-16, Massachusetts Institute of Technology, 
Oct. 1, 1943. Div. 11-204.1-MI 

4. Naval Aircraft Coatings (Progress Report covering 

90-day period ending Apr. 30, 1942), A. J. Weith 
and V. H. Turkington, OEMsr-211, Bakelite Corp., 
June 5,1942. Div. 11-206.11-M3 

5. Protective Coatings for Magnesium Alloys (Pre¬ 

liminary Report covering period ending Oct. 31, 
1943), OSRD 2094, OEMsr-211, Bakelite Corp., Nov. 
30, 1943. Div. 11-206.11-M8 

6. Coatings for Wood Ship Bottoms, OSRD 4044, 

OEMsr-211, Service Project NL-B4, Bakelite Corp., 
Aug. 21, 1944. Div. 11-206.11-M10 

7. Evaluation Procedures for Water Repellency Treat¬ 

ments Vol. 1 (Final Report for the period from Jan. 
1, 1943, to Dec. 31,1944), Arnold M. Sookne, Francis 
W. Minor, and others, OEMsr-1055, Service Project 
QMC-20, National Bureau of Standards, January 
1945. Div. 11-208.12-MI 

8. Prevention of Degradation of Impregnated Clothing 

(Final Report for the period from July 1, 1943, 
through Dec. 31,1944), Henry A. Rutherford, Julian 
Berch, and others, OEMsr-1055, Service Project 
QMC-29, National Bureau of Standards, January 
1945. Div. 11-208.14-MI 





BIBLIOGRAPHY 


197 


9. Plastic Laminated Structures Used as Armor (Final 
Report for the period from Dec. 1, 1943, to May 31, 
1944), L. S. Meyer and J. C. Case, OEMsr-1055, 
Service Project QMC-30-I, Libbey-Owens-Ford 
Glass Co., June 1944. Div. 11-208.21-MI 

10. Evaluation of Plastic Materials and Development 
of Production Testing (Final Report for the period 
from Jan. 1, 1944, to June 30, 1944), R. W. Auxier 
and K. L. Landon, OEMsr-1055, Service Project 
QMC-30-C, Westinghouse Electric and Manufactur¬ 
ing Co., July 1944. 

11. Plastic Laminates Used as Armor, Vol. I, (Final Re¬ 

port for the period from Dec. 1, 1943, to Nov. 1, 
1944), H. W. Mohrman and D. Telfair, OEMsr-1055, 
Service Project QMC-30-F, Monsanto Chemical Co., 
November 1944. Div. 11-208.21-M3 

12. Dor on. Plastic Laminates Used as Armor (Final 

Report for the period from Dec. 11, 1943, to Oct. 31, 
1944), Nelson J. Anderson and J. G. Wisler, OEMsr- 
1055, Service Project QMC-30-G, American Cyana- 
mid Co., November 1944. Div. 11-208.21-M4 

13. Dor on. Plastic Laminates Used as Armor, Vol. II 
(Final Report for the period from Oct. 31, 1944, to 
June 30,1945), Nelson J. Anderson and J. G. Wisler, 
Contract W44-109 qm-305, Service Project QMC-30- 
G, American Cyanamid Co., June 1945. 

14. Investigation of Ballistic Properties of Dor on (Final 
Report for the period Nov. 1, 1943, to Nov. 1, 1944), 
Howard J. Billings, OEMsr-1055, Service Project 
QMC-30-B, Arthur D. Little, Inc., November 1944. 

Div. 11-208.22-MI 


15. Theory of the Ballistic Resistance of Flat Plates and 
Its Application to Doron (Final Report for the pe¬ 
riod from Dec. 1, 1943, to Jan. 31, 1945), E. L. 
Thearle, OEMsr-1055, Service Project QMC-30-D, 
General Electric Co., February 1945. 

Div. 11-208.22-M2 

16. The Light Armor Testing Laboratory and Research 
Relating Thereto, Vol. II, (Final Report for the pe¬ 
riod from Nov. 1, 1944, to Dec. 31, 1945), Howard 
J. Billings, Contract W44-109 qm-305, Service Proj¬ 
ect QMC-30-B, Arthur D. Little, Inc., January 1946. 

Div. 11-208.22-M3 

17. The 20-mm Side Spray Test for the Evaluation of 
Doron, Vol. II, (Final Report for the period from 
Nov. 1, 1944, to Dec. 31, 1945), Howard J. Billings, 
Contract W44-109 qm-305, Service Project QMC- 
30-B, Arthur D. Little, Inc., January 1946. 

Div. 11-208.22-M4 

18. Physical Testing of Doron, LeRoy W. Clark, OEMsr- 

1055, Service Project QMC-30-A, Rensselaer Poly¬ 
technic Institute. Div. 11-208.22-M5 

19. Flame Throwers, Incendiaries and Their Evalua¬ 

tion, Abbot Byfield, W. A. Klemm, and G. A. Agos- 
ton, OSRD 6190, OEMsr-21, Service Project CWS-10 
and CWS-21, Massachusetts Institute of Technology, 
Oct. 1, 1945. Div. 11-300-MI 

20. Tests Conducted on Incendiary Program at Dugway 

Proving Ground, Simpson Springs, Utah, between 
Aug. 3 and Oct. 20,1943, H. A. Ricards, Jr., OEMsr- 
354, Report PDN-1764, Standard Oil Development 
Co., Nov. 5, 1943. Div. 11-301.1-MI 




OSRD APPOINTEES 


DIVISION 11 


Division 11 was organized on December 9, 1942 when 
former Division B of the NDRC was broken up into four 
new Divisions, 8, 9, 10, and 11, known as the Chemical 
Divisions. Former Division B was under the Chairman¬ 
ship of Roger Adams and had ten sections, each of which 
had one or more subsections. Division 11 was made up 
of Sections B-7, B-8, part of B-9, and B-10 (together with 
subsections B-7-b, B-7-d, B-7-e, B-8-a, B-8-b, B-8-c, B-8-d, 
B-8-e, B-8-f, B-9-a, and B-9-d) of former Division B. 
Subsections B-9-b and B-9-c of Section B-9 were later in¬ 
corporated in a new Division 19. 

The list which appears below therefore shows essen¬ 


tially the organization since December 9, 1942. Although 
many changes were made during the years 1943-1945, 
the names of all appointees who held appointments to 
Division 11 at any time during this period have been in¬ 
cluded. In addition the names of men who held appoint¬ 
ments in the sections and subsections of former Division 
B, but who did not have appointments to Division 11 fol¬ 
lowing the reorganization, have been included so as to 
give a complete picture of the organization since the 
beginning of the work under NDRC. 

Section 11.2 comprises Subsections B-8-a, B-8-b, B-8-c, 
B-8-d, B-8-e, B-8-f, B-9-a, and B-9-d of former Division B. 


Chiefs 

R. P. Russell 
E. P. Stevenson 
H. M. Chadwell 


Technical Aide 

D. Churchill, Jr. 


Members 

D. Churchill, Jr. W. K. Lewis 

E. R. Gilliland J. H. Rushton 

H. C. Hottel R. P. Russell 

H. F. Johnstone T. K. Sherwood 

E. P. Stevenson 


SECTION 2 

Chiefs 
W. K. Lewis 
T. K. Sherwood 

Technical Aides 


198 


A. Byfield 
W. Dietz 


F. E. Vinal 
R. C. Wilcox 



OSRD APPOINTEES 

(Continued) 


Members 


T. A. Boyd 

A. L. Henne 

T. M. Carpenter 

H. C. Hottel 

E. K. Carver 

W. K. Lewis 

C. M. Cooper 

E. Mack, Jr. 

G. 0. Curme 

D. A. Maclnnes 

G. H. B. Davis 

F. W. Maurer 

C. K. Drinker 

T. Midgley 

E. F. DuBois 

V. H. Turkington 

F. H. Dutcher 

A. J. Weith 

M. R. Fenske 

D. B. Williams 


J. C. Zimmer 



mm 


199 





CONTRACT NUMBERS, CONTRACTORS AND SUBJECT OF CONTRACTS 


Contract Number 


Name and Address of Contractor 


Subject 


NDCrc-3 (11-20) 
NDCrc-15 (11-23) 
NDCrc-29 (11-22) 
NDCrc-37 (11-29) 
NDCrc-42 (11-27) 
NDCrc-50 (11-28) 
NDCrc-69 (11-48) 
NDCrc-92 (11-68) 
NDCrc-165 (11-85) 
OEMsr-6 (11-108) 
OEMsr-23 (11-115) 
OEMsr-52 (11-97) 
OEMsr-82 (11-149) 

OEMsr-104 (11-170) 
OEMsr-130 (11-154) 
OEMsr-158 (11-179) 
OEMsr-186 (11-152) 
OEMsr-189 (11-209) 
OEMsr-196 (11-190) 
OEMsr-204 (11-223) 

200 


Ethyl Gasoline Corporation, 

Detroit, Michigan 

University of Wisconsin, 

Madison, Wisconsin 

Princeton University, 

Princeton, New Jersey 

Monsanto Chemical Company, 

Dayton, Ohio 

Bakelite Corporation, 

Bloomfield, New Jersey 

University of Illinois, 

Urbana, Illinois 

Harvard University, 

Cambridge, Massachusetts 

Wesleyan University, 

Middletown, Connecticut 

Pennsylvania State College, 

State College, Pennsylvania 

Massachusetts Institute of Technology, 
Cambridge, Massachusetts 

Harvard University, 

Cambridge, Massachusetts 

Bakelite Corporation, 

Bloomfield, New Jersey 

Arthur D. Little, Inc., 

Cambridge, Massachusetts 


Columbia University, 

New York City 

Rockefeller Institute, 

New York City 

Wesleyan University, 
Middletown, Connecticut 

Pennsylvania State College, 
State College, Pennsylvania 

Rice Institute, 

Houston, Texas 


Oil and Gasoline Sabotage 


Drying of Gases 


Paint Removers 


Gasoline Sabotage 


Protective Coatings 


Removal of Salts from Sea 
Water 

Oxygen Breathing Equipment 


Flash Powders for Aerial 
Night Photography 

Hydraulic Fluids 


Evaporation of Drops 


Oxygen Breathing Equipment 


Protective Coatings 


Investigation of the Use of 
Substitute Materials in the 
Manufacture of Cork Plugs 
Used in Naval Ordnance 

Canister Design Calculations 


Vesicant Thickening 


Underwater Flares 


Hydraulic Fluids 


Sabotage of Lubricating Oils 


Harvard University, Oxygen Breathing Equipment 

Cambridge, Massachusetts 

Harvard University, Report on Anti-fouling Paints 

Cambridge, Massachusetts 






CONTRACT NUMBERS, CONTRACTORS AND SUBJECT OF CONTRACTS 

( Continued) 


Contract Number 
OEMsr-211 (11-219) 

OEMsr-231 (11-169) 

OEMsr-283 (11-230) 

OEMsr-306 (11-240) 

OEMsr-320 (11-242) 

OEMsr-321 (11-260) 

OEMsr-341 (11-247) 

OEMsr-347 (11-111) 
OEMsr-408 (11-271) 
OEMsr-425 (11-273) 

OEMsr-428 (11-283) 

OEMsr-446 (11-218) 
OEMsr-506 (11-343) 

OEMsr-565 (11-301) 


Name and Address of Contractor 


Subject 


Bakelite Corporation, 
Bloomfield, New Jersey 

Ethyl Gasoline Corporation, 
Detroit, Michigan 

Resinous Products, 

Philadelphia, Pennsylvania 

Harvard University, 

Cambridge, Massachusetts 


Harvard University, 

Cambridge, Massachusetts 

Wesleyan University, 
Middletown, Connecticut 


University of Cincinnati, 
Cincinnati, Ohio 


Massachusetts Institute of Technology, 
Cambridge, Massachusetts 


Protective Coatings 

I 

Oil and Gasoline Sabotage 


Potable Water from Sea 
Water 

Data on Instantaneous Rates 
of Flow During Inspiration 
and Expiration 

Oxygen Breathing Equipment 


Development of Photoflash 
Bombs and Underwater 
Flares 

Methods of Purification of 
Water After its Transpor¬ 
tation and Storage in Cans, 
Drums, and Tanks that 
have been Employed as 
Containers for Leaded Gas¬ 
oline 

Canister Design 


Pennsylvania State College, Hydraulic and Recoil Fluids 

State College, Pennsylvania 


Mine Safety Appliances Company, 
Pittsburgh, Pennsylvania 


Ethyl Corporation, 
Detroit, Michigan 


Bakelite Corporation, 

Bloomfield, New Jersey 

E. I. du Pont de Nemours and Company, 
Wilmington, Delaware 


Catholic University, 
Washington, D. C. 


HHI 


Development of Methods of 
Protecting Gasoline Tanks, 
Wing Spaces, and Cockpits 
Against Hazard of Explo¬ 
sive Mixtures of Gasoline 
and Air 

Preliminary Engine Studies 
of Methods of Sabotage of 
Lubricating Oils 

Mechanical Methods of Clean¬ 
ing Ship Bottoms 

Investigation of Methods of 
Removal of Dust from Air 
Supplied to Aircraft En¬ 
gines 

Preliminary Investigation of 
Possibilities of Increasing 
the Capacity of Lead Sto¬ 
rage Batteries by Modifica¬ 
tion of the Negative Plate 

201 



















CONTRACT NUMBERS, CONTRACTORS AND SUBJECT OF CONTRACTS 

(Continued) 


Contract Number 


Name and Address of Contractor 


Subject 


OEMsr-606 (11-299) 


E. I. du Pont de Nemours and Company, 
Wilmington, Delaware 


OEMsr-672 (11-342) 


University of California, 
Berkeley, California 


OEMsr-743 (11-359) 
OEMsr-796 (11-377) 


E. I. du Pont de Nemours and Company, 
Wilmington, Delaware 

E. I. du Pont de Nemours and Company, 
Philadelphia, Pennsylvania 


OEMsr-820 (11-390) 


Harvard University, 

Cambridge, Massachusetts 


OEMsr-844 (11-410) 


Universal Oil Products Company, 
Riverside, Illinois 


OEMsr-873 (11-391) 


Monsanto Chemical Company, 
Everett, Massachusetts 


OEMsr-896 (11-419) 
OEMsr-897 (11-409) 


The Texas Company, 
New York City 

The Texas Company, 
New York City 


OEMsr-928 (11-437) 


E. I. du Pont de Nemours and Company, 
Wilmington, Delaware 


OEMsr-930 (11-436) 


National Research Corporation, 
Boston, Massachusetts 


OEMsr-946 (11-446) 


Continental Can Co., Inc., 
New York City 


OEMsr-953 (11-431) 


E. I. du Pont de Nemours and Company, 
Wilmington, Delaware 


OEMsr-1017 (11-421) 


Massachusetts Institute of Technology, 
Cambridge, Massachusetts 


Experimental Studies of the 
Effect of Physical Proper¬ 
ties of Viscous Fluids on the 
Break-up of Liquid Jets and 
Drops When Contacted by 
Air Stream 

Investigation of the Removal 
of Oil from Harbor Waters 
by Means of Chemically 
Treated Sand 

Development of Vesicant 
Thickeners 

Linings for Fuel, Munitions, 
and Lubricant Containers; 
and Sealants for Navy 
Fuzes 

Study of Methods of Anaero¬ 
bic Conversion of Urea to 
Ammonia and Aerobic Con¬ 
version of Ammonia to Ni¬ 
trates 

Pilot Plant Studies of the 
Purification of Levinstein 
Mustard 

Design of Equipment for Pro¬ 
ducing Nitric Acid in China 
from Dilute Ammonia Solu¬ 
tions 

Sabotage of Automotive 
Equipment < 

Pilot Plant Studies of the 
Purification of Levinstein 
Mustard by Solvent Extrac¬ 
tion and Flash Distillation 

Study of Sodium Hydride- 
Aluminum Mixtures Suita¬ 
ble for Field Generation of 
Hydrogen 

Development of Nonelectro- 
lytic Method of Producing 
Lithium Hydride from Ores 

Development of Hydrogen 
Generators for the Use of 
Sodium Hydride-Aluminum 
Mixtures 

Evaluation of Processes for 
Producing Sodium Boro- 
hydride 

Purification of Mustard 


202 







CONTRACT NUMBERS, CONTRACTORS AND SUBJECT OF CONTRACTS 

( Continued ) 


Contract Number 


Name and Address of Contractor 


OEMsr-1047 (11-462) 


Arthur D. Little, Inc., 

Cambridge, Massachusetts 


OEMsr-1164 (11-471) 
OEMsr-1169 (11-473) 


Massachusetts Institute of Technology, 
Cambridge, Massachusetts 

Massachusetts Institute of Technology, 
Cambridge, Massachusetts 


OEMsr-1194 (11-476) 


University of Indiana, 
Bloomington, Indiana 


OEMsr-1206 (11-479) 
OEMsr-1223 (11-474) 
OEMsr-1244 (11-478) 
OEMsr-1259 (11-485) 


General Printing Ink Corporation, 
New York City 

Comstock and Wescott, Inc., 
Niagara Falls, New York 

Curtiss-Wright Corporation, 
Buffalo, New York 

Rutgers University, 

New Brunswick, New Jersey 


OEMsr-1271 (11-482) 

OEMsr-1354 (11-502) 
OEMsr-1373 (11-506) 
OEMsr-1395 (11-507) 
OEMsr-1452 (11-510) 
OEMsr-1453 (11-509) 
OEMsr-1465 (11-513) 


Rice Institute for the Advancement of Litera¬ 
ture, Science and Art, 

Houston, Texas 

Grinnell Corporation, 

Providence, Rhode Island 

General Printing Ink Corporation, 

New York City 

E. I. du Pont de Nemours and Company, 
Wilmington, Delaware 

University of Illinois, 

Urbana, Illinois 

Massachusetts Institute of Technology, 
Cambridge, Massachusetts 

Massachusetts Institute of Technology, 
Cambridge, Massachusetts 


CONTRACTS ON QUARTERMASTER PROBLEMS 

OEMsr-718 (11-375) University of Cincinnati, 

Cincinnati, Ohio 


OEMsr-854 (11-415) 


Ethyl Corporation, 
Detroit, Michigan 



Subject 


Development of Distilling 
Units for the Manufacture 
of Potable Water from Sea 
Water 

Development of Solar Still 

Gas Generator for Pressuriz¬ 
ing Flame Throwers. More 
Rapid Inflation of Life 
Rafts in Cold Waters 

Investigation of Methods of 
Producing Magnesium Flu¬ 
oride 

Plane Crash Dye Markers 

Marine Type Electrocoating 
for Gasoline Containers 

Protection of Airplane Fuel 
Tanks from Explosion 

Effect of Marine Organisms 
on Corrosion and Paint De¬ 
gradation 

Suppression of Dust by 
Ground Treatment 

Gas Generator for Pressuriz¬ 
ing Flame Throwers 

Advance Positions Identifica¬ 
tion 

Exterior Ballistics of Liquid 
Filled Shell 

Concentrated Hydrogen Per¬ 
oxide 

Concentrated Hydrogen Per¬ 
oxide 

Investigation of Preparation 
of Dilute Hydrogen Perox¬ 
ide by Application of Fluid 
Catalyst Technique 


Studies and Investigations in 
Connection with the Im¬ 
provement of Wearing 
Qualities of Leather for 
Military Uses 

Deleading of Gasoline 


203 













CONTRACT NUMBERS, CONTRACTORS AND SUBJECT OF CONTRACTS 

( Continued ) 


Contract Number 


Name and Address of Contractor 


Subject 


OEMsr-862 (11-411) 


OEMsr-888 (11-418) 
OEMsr-929 (11-430) 
OEMsr-1014 (11-450) 


OEMsr-1055 (11-500) 

OEMsr-1055 (11-500) 
AN-20 (sub-contract) 

OEMsr-1055 (11-500) 
QMC-7 (sub-contract) 

OEMsr-1055 (11-500) 
QMC-17 (sub-contract) 


OEMsr-1055 (11-500) 
QMC-19A (sub-contract) 

OEMsr-1055 (11-500) 
QMC-20 (sub-contract) 

OEMsr-1055 (11-500) 
QMC-22 (sub-contract) 

OEMsr-1055 (11-500) 
QMC-23 (sub-contract) 

OEMsr-1055 (11-500) 
QMC-24 (sub-contract) 


Textile Foundation, National Bureau of Stand- Water Repellent Treatment 
ards, 

Washington, D. C. 


Massachusetts Institute of Technology, 
Cambridge, Massachusetts 

Massachusetts Institute of Technology, 
Cambridge, Massachusetts 

Smithsonian Institution, 

Washington, D. C. 


National Academy of Sciences, 
Washington, D. C. 

Mellon Institute of Industrial Research, 
Pittsburgh, Pennsylvania 


Worcester Polytechnic Institute, 
Worcester, Massachusetts 

University of Cincinnati, 
Cincinnati, Ohio 


University of Chicago, 

Chicago, Illinois 

Textile Foundation, Bureau of Standards, 
Washington, D. C. 

Massachusetts Institute of Technology, 
Cambridge, Massachusetts 

Massachusetts Institute of Technology, 
Cambridge, Massachusetts 

Smithsonian Institution, 

Washington, D. C. 


Rot and Termite Prevention 


Troop Feeding Program 


Military Ski Poles, West¬ 
ern Hemisphere Bamboo, 
Sources for 

QMC Problems 


Development of Suitable 
Buoyant Material for Use 
in Life Vests, etc. 

Leather Sole; Substitute for 


Studies and Investigations in 
Connection with the Im¬ 
provement of Wearing 
Qualities of Leather for 
Military Uses 

Deleading of Gasoline 


Water Repellent Treatment 


Rot and Termite Prevention 


Troop Feeding Program 


Military Ski Poles, West¬ 
ern Hemisphere Bamboo, 
Sources for 


OEMsr-1055 (11-500) 
QMC-27 (sub-contract) 


Columbia University, 
New York City 


Flameproofing 


OEMsr-1055 (11-500) 
QMC-29 (sub-contract) 

OEMsr-1055 (11-500) 
QMC-30A (sub-contract) 

OEMsr-1055 (11-500) 
QMC-30B (sub-contract) 

OEMsr-1055 (11-500) 
QMC-30C (sub-contract) 

OEMsr-1055 (11-500) 
QMC-30D (sub-contract) 


Textile Foundation, National Bureau of Stand- Impregnated Clothing 
ards, 

Washington, D. C. 

Rensselaer Polytechnic Institute, Doron 

Troy, New York 

Arthur D. Little, Inc., Doron 

Cambridge, Massachusetts 

Westinghouse Electric Mfg. Co., Doron 

East Pittsburgh, Pennsylvania 

General Electric Company, Doron 

Schenectady, New York 


miaiii 




204 









CONTRACT NUMBERS, CONTRACTORS AND SUBJECT OF CONTRACTS 

( Continued ) 


Contract Number 


Name and Address of Contractor 


OEMsr-1055 (11-500) 
QMC-30F (sub-contract) 

OEMsr-1055 (11-500) 
QMC-30G (sub-contract) 

OEMsr-1055 (11-500) 
QMC-30I (sub-contract) 

OEMsr-1055 (11-500) 
QMC-31 (sub-contract) 

OEMsr-1055 (11-500) 
QMC-32 (sub-contract) 

OEMsr-1055 (11-500) 
QMC-33 (sub-contract) 

OEMsr-1055 (11-500) 
QMC-34 (sub-contract) 

OEMsr-1055 (11-500) 
QMC-36 (sub-contract) 


Monsanto Chemical Company, 

Dayton, Ohio 

American Cyanamid Company, 

1937 West Main St., 

Stamford, Connecticut 

Plaskon Division of Libby Owens Ford Company 


Temple University, 

Philadelphia, Pennsylvania 

Brooklyn Polytechnic Institute, 

Brooklyn, New York 

Massachusetts Institute of Technology, 
Cambridge, Massachusetts 

Textile Foundation, National Bureau of Stand¬ 
ards, 

Washington, D. C. 

Brooklyn Polytechnic Institute, 

Brooklyn, New York 


Subject 


Dor on 

■ 

Doron 


Doron 

Organic Coatings 

Thin Films from Synthetic 
Elastomers 

Wear Resistance of Apparel 
Textiles 

Shrinkproofing of Wool Knit 
Items and Fabrics 

Improvement of Coated Fab¬ 
rics 


205 

















SERVICE PROJECTS 


The projects listed below were transmitted to the Executive 
Secretary, NDRC, from the War or Navy Department through 
either the War Department Liaison Office for NDRC or the Office 
of Research and Inventions (formerly the Coordinator of Research 
and Development), Navy Department. 


Service 


Project 

Number 

Title 


AC-2 

AC-7 

AC-8 

AC-29 

AC-38 

AC-93 

CE-19 


CWS-1 

CWS-4 

CWS-5 

CWS-7 

CWS-10 

CWS-12 

CWS-13 

CWS-15 

CWS-16 

CWS-21 

CWS-31 

OD-61 

OD-130 

OD-154 

QMC-17 


QMC-19 

QMC-20 

QMC-22 

QMC-23 


Army Projects 

Research on Fuels, Fuel Additives, and Lubricant Additives. 

Constant Viscosity Hydraulic Fluid. 

Hydraulic Packing Material. 

Miscellaneous Research on Photographic Equipment. 

Development of Oxygen Mask Embodying the Principle of 
Full Head Coverage and Equipped with Antifog Goggles. 

Data on Instantaneous Rates of Flow During Inspiration 
and Expiration. 

Determination of a Suitable and Practicable Method for 
Cleaning Gasoline Containers to Make Them Safe for 
Holding Drinking Water. 

Aerosols—Their Generation, Stabilization and Precipita¬ 
tion. 

Methods of Preparation of Certain Non-arsenical Organic 
Compounds. 

Test of Pro-knock Materials: Special Problems Relating to 
Internal Combustion Engines. 

Fundamental Study of Gas Mask Absorbents. 

Gas Generator for Pressurizing Flame Throwers. 

Materials for Thickening and Increasing the Viscosity of 
Vesicants. 

Catalyst for Prevention of Corrosion of Steel Containers by 
Liquid Vesicants. 

Improved Filter Materials. 

Improved Filter Design. 

Study of Incendiary Materials. 

Exterior Ballistics of Liquid-Filled Shell. 

Development of Ideal Recoil Oil. 

Anti-Corrosive Linings for Gasoline Containers. 

Suppression of Dust of Flash Around Field Guns. 

Investigation of Leathers, tanning methods and special 
treatment to leather for the purpose of making leathers 
most adaptable to military use and increasing its service¬ 
ability. 

Deleading of Gasoline. 

Water Repellency Treatments: evaluation procedures for 

Insect Damage to QM Equipment; survey of Present Knowl¬ 
edge of Dangers and Prevention. 

Troop Feeding Program, a Critique and Compilation of 
Available Information. 







SERVICE PROJECTS 
( Continued) 


Service 

Project 

Number 

Title 

QMC-24 

QMC-28 

SC-44 

SOS-12 

Army Projects 

Substance for Bamboo for Military Purposes. 

Marine Electroplating Process. 

Improved Hydrogen Generation Methods. 

Development of Material for Marking Foliage for Identifica¬ 
tion of Position by Planes. 

NA-105 

NA-122 

Navy Projects 

Protection of Aircraft Fuel System Against Gunfire. 

Improvement of Organic Protective Coatings for Use on 

Naval Aircraft. 

% 

NE-100 

NE-102 

Plane Crash Dye Marker. 

Design of Rubber Life Raft; extension to include more rapid 
inflation of life rafts. 

NL-Bl(i) 

Problems Related to the Manufacturing and Use of Potas¬ 
sium Peroxide in Oxygen Breathing Equipment. 

NL-B2 

Development of Non-toxic and Non-inflammable Paint Re¬ 
movers. 

NL-B4 

NL-B5 

NL-B36 

Protective Coatings. 

Methods of Rendering Sea Water Potable. 

Study of Spreading of Droplets of All Types of Mustard 

Gas and Lewisite on Cloth and on Metal and Painted Sur¬ 
faces. 

NO-B37 

NO-126 

Substitute for Cork in Ordnance Plugs. 

Study of Suitable Containers for Various Types of Corro¬ 
sive Chemical and Smoke-Producing Agents. 

NO-189 

Development of Improved Method of Producing Pure Mag¬ 
nesium Fluoride. 

NO-266 

Investigation and Development of Petroleum and Non-Pe¬ 
troleum Hydraulic Fluids. 

NO-288 

NS-103 

NS-110 

Sealing Agent (s) for Projectile Base Fuzes. 

Removal of Oil or Gasoline Film from Surface of Water. 

Possible Improvements on Submarine Storage Batteries and 

Other Lead Storage Batteries. 

NS-129 

NS-168 

Development of Fireproof Paint. 

Development of Distilling Units for the Manufacture of 

Potable Water from Sea Water; extension to include 

Solar Energy-Type Stills. 

NS-235 

Research on the Effect of Micro-Organisms on Corrosion. 

AN-13 

Army-Navy Projects 

Development of Non-contaminating 55-gallon Drums for 
Petroleum Products. 

Chinese-1 

NACA-1 

SAC-9 

Neither Army nor Navy Projects 

Nitric Acid from Urea. 

Removal of Dust from Air Intake of Aircraft. 

Sabotage of Automotive Equipment. 

Hhhi 


207 


















































































































































INDEX 


The subject indexes of all STR volumes are combined in a master index printed in a separate volume. 
For access to the index volume consult the Army or Navy Agency listed on the reverse of the half-title page. 


Abrasion resistance tests; apparel 
fabrics, 174-175 
leather substitutes, 138 
Abrasive cleaning methods, 103 
Acryloid polymers, in hydraulic 
fluids, 4-5 

blending efficiency, 4 
blending procedure, 9 
centistoke viscosity, 4 
effect of molecular weight on vis¬ 
cosity, 4-6 
solubility, 4 

Acrysol for noninflammable hydrau¬ 
lic fluids, 12 

Activated carbon; burner for fuel 
tank explosion prevention, 
16-17 

cleaner for gasoline containers, 
116 

Adhesion; anti-corrosive paints, 
92-93 

sealants for primers and fuzes, 
114 

Adhesives for Army shoes, 139-140 
ADP (ammonium dihydrogen phos¬ 
phate) as flameproofing 
agent, 163 

Aerial camera, high speed, 28 
AF-14 antifouling paint, 102 
AF-22 antifouling paint, 102 
Aircraft crash dye marker, 47-48 
Aircraft engine, dust protection, 
14-15 

Aircraft fuel tanks, explosion pre¬ 
vention, 16-19 

Aircraft hydraulic fluids, 2, 7, 9, 10 
Aircraft vesicant sprays, tactical 
uses, 61-62 

Airflow in breathing; 

77-80 

field studies, 82 

flow meter for instantaneous 
measurements, 77 
instantaneous respiration rates, 
77-80 

research recommendations, 83 
respiratory resistance, 80-82 
valves in respiratory masks, 80 
Ajax 3P2 induction furnace, 118 
Aldol for lubricating oil sabotage, 
87 

Alginates for treatment of soil for 
dust suppression, 128 


Alkalex, 88 

Alkyd resin base paint, 109 
Alrose shrinkproofing process, 176 
Althouse shrinkproofing process, 
176 

Aluminum surface preparation for 
good paint adherence, 94 
Amberlite IR-1, 88 
Amberlite IR-4, 88 
Ammonium dihydrogen phosphate 
for flameproofing, 163 
Ammonium halides for flameproof¬ 
ing, 163 

Ammonium sulfamate for flame¬ 
proofing, 163 

Amyl nitrate, as proknock, 85 
Anaerobic corrosion of metals in 
sea water, 104-107 
see also Corrosion 
Anex for removing salt from sea 
water, 88 

Aniline in petroleum testing, 7 
Anion exchangers for potable sea 
water, 88 

Antiaircraft guns, hydraulic fluid 
requirements, 3 

Anticorrosive coatings; see Corro¬ 
sion resistant coatings and 
linings 

Antifouling coatings for Navy ves¬ 
sels, 97-102 

AF-14 antifouling paint, 102 
AF-22 antifouling paint, 102 
copper leaching tests, 98-99 
effect of rosin, 100 
exposure tests, 100-102 
for wood-bottom ships, 102 
hot plastic coating, 97-98 
permeability to ions, 100 
ratio of copper to binder, 100-101 
recommended coating systems, 
101-102 

theories of fouling prevention, 
98-99 

use of nontoxic inorganic fillers, 
100 

Antimony oxide in fire retardant 
paint, 107 

Antioxidants in high polymers, 171 
Antisubmarine underwater flare, 
20-22 

AN-VV-0-366a, b hydraulic fluid, 
5, 7, 10 


Apparel textiles, wear resistance, 
173-175 

Argon, research recommendation 
for high intensity flash 
bombs, 26 

Aroclor 1254, plasticizer for anti¬ 
corrosive coating, 114, 115 
Aromatic hydrocarbons in hydrau¬ 
lic fluids; effect on synthetic 
rubber gaskets, 8 
removal from crude oil, 7 
Arsenic trichloride as proknock, 85 
Arsenious acid anhydride as pro¬ 
knock, 85 

Artillery emplacements, dust sup¬ 
pression, 127-131 

Atlas Powder K oil as tung oil sub¬ 
stitute, 164 

Aurand paint removal tool, 103-104 
Automatic pilot steering equipment, 
hydraulic fluid, 1 

Aviation fuel; gasoline sabotage, 
86 

proknocks as sabotage device, 84- 
85 

temperature range for explosive 
hazards, 16 

AXS-808 recoil oil, 7, 9 
service tests, 11 

Bacterial effects on metal corrosion 
and paint degradation, 104- 
107 

anaerobic corrosion, 104-105 
exposure tests, 105-107 
Bakelite modified linseed oil as tung 
oil substitute, 164 

Bakelite XV-1657 as anticorrosive 
coating, 114 

Ballistics of liquid filled shells; see 
Liquid filled shells, exterior 
ballistics 

Ballistics testing machine for lab¬ 
oratory use, 68-70 
Bamboo for ski pole shafts, 153-155 
fabrication, 153 
performance tests, 153 
Bancroft fabric flame retardant ef¬ 
ficiency, 161 

Barium process for production of 
hydrogen peroxide, 135-137 
Barrier type photocell for light in¬ 
tensity measurements, 20 


209 


210 


INDEX 


Base exchange materials for pro¬ 
duction of drinking water 
from sea water, 88 
Batteries, storage, modifications 
for increased capacity, 120 
Beckacite, super no. 1000 for gaso¬ 
line sabotage, 86 

ra-Benzenedisulfonic acid for sabo¬ 
taging lubricating oil, 86 
Benzoyl peroxide, effect on degrada¬ 
tion of high polymers, 170 
Bicycle ergometer curves, respira¬ 
tion rate studies, 78-90 
Blast deflectors for dust reduction 
around artillery emplace¬ 
ments, 127 

Blast mats for dust suppression 
around artillery emplace¬ 
ments, 129-131 
canvas, 129 
fabrication, 130 
neoprene, 130 
nylon, 129 
vinylite, 130 

BLB oro-nasal oxygen mask type 
A-8, 49 

Bleach; see Chlorinated lime 
Blending efficiency of acryloid poly¬ 
mers, 5 

Blending procedures for polymer- 
containing hydraulic fluids, 9 
Blistering of paints; anticorrosive 
paint films, 94-95 
fire hazard, 108 

Blocking characteristics of plastic 
hot melts for ration packag¬ 
ing, 178, 179, 181 

Blotter pressing of petroleum base 
stock for contamination re¬ 
moval, 7 
Blue 4B dye, 38 
Blue 6B dye, 38 
Blue 0 dye, 38 
Blue 04B dye, 38 

Borax as flameproofing agent, 160, 
163 

Boric acid as flameproofing agent, 
160, 163 

BR254 for food can varnishes, 165 
Brakes, hydraulic fluid for, 1 
Breathing; evaluation of maximum 
allowable respiratory resist¬ 
ance, 80-82 
field studies, 82 

measurement of instantaneous 
respiration rates, 77-80 
simulated by testing device, 77- 
78 

Bristol gun turret, 10 


British Mk III aluminum dust 
bomb, 20 

Brookfield synchrolectric viscosi¬ 
meter, 179 

Brownian movement in molecular 
model for elastomers, 167 
Buffalo Electrochemicals Co., 132 
Buna N in shoe adhesives, 140 
w-Butyl dichlorophosphine as pro¬ 
knock, 85 

n-Butyl sulfide as proknock, 85 
Butyl thionitrate as proknock, 85 

Cadmium plate, surface prepara¬ 
tion for paint adherence, 94 
Calcium hydride as source of hydro¬ 
gen for meteorological bal¬ 
loons, 45 

Camera for high speed motion pic¬ 
ture studies of photoflash 
bombs, 28-31 

Canister charcoal, acceptance tests, 
,78 

Carbic anhydride linseed resin, as 
binder in fire retardant wa¬ 
ter emulsion paint, 109 
Carbic Color and Chemical Co. dyes, 
38 

Carbide and Carbon Chemicals 
Company, 4, 12 

Carbon, activated; burner for fuel 
tank explosion prevention, 
16-17 

cleaner for gasoline containers to 
be used in transporting 
drinking water, 116 
Carbon dioxide inflated life rafts; 
disadvantages, 32, 33 
inflation system, 32, 33 
proposed modifications, 33-36 
Carbonaceous fuels for heating 
combat rations, literature 
search, 158-159 

Carbowax 4000 fuel unit for heat¬ 
ing combat rations, 157 
Carnivores, damage to Quartermas¬ 
ter items, 149 

Casings of photoflash bombs; opti¬ 
mum confinement for flash 
powder types, 25 
steel casing tests results, 24-25 
Castor oil, dehydrated, as tung oil 
substitute, 164 

Catex, for removing salt from sea 
water, 88 

Cation exchangers for producing 
drinking water from sea wa¬ 
ter, 88 

Cellulose sponge for absorption of 
mustard gas, 64 


Centistoke viscosity; acryloid pol¬ 
ymers, 4-6 
hyrdaulic fluids, 8-9 
Levinstein H, thickened solutions, 
56-57 

Cesium oxide photoelectric cells 
in oscillograph flash photom¬ 
eter, 27 

Cetron CE-31-V photoelectric cell 
in oscillograph flash photom¬ 
eter, 27 

Chaetomium globosum, resistance 
of plastic hot melts, 181 
Channel air filter for dust removal 
from air ducts, 14 
Charcoal canister, acceptance tests, 
77, 78 

Charcoal for heating combat ra¬ 
tions, 158-159 

Chemical Warfare Service gas- 
proofed-flameproofed fabric, 
flame retardant efficiency, 

161 

Chemical Warfare Service-Massa- 
chusetts Institute of Tech¬ 
nology treated fabric, flame 
retardant efficiency, 161 
Chinawood oil for gasoline sabo¬ 
tage, 86 

Chlorinated hydrocarbons for use 
as hydraulic fluids, 3-4 
Chlorinated lime, storage behavior; 
catalytic action by iron and 
ferric oxide, 184 

effect of moisture content on tem¬ 
perature of reaction, 184 
heat of decomposition, 183, 184 
heat of reaction with oxidizable 
impurities, 183-184 
hygroscopicity, 184 
relationship of pH to stability, 
184 

specifications, 185 
Chlorinated styrene, resistance to 
bacteria, 107 

2-Chloroethyl nitrite as proknock, 
85 

6is-/3-Chloroethyl sulfide; in Levin¬ 
stein H mustard gas, 54, 55 
rate of evaporation, 62 
Chloroform, use as proknock, 85 
1-Chloro-l-nitropropane; use as 
proknock, 85 

p-Chlorophenol, as leather disin¬ 
fectant, 141 

Chlorosulfonic acid-sulfur trioxide 
smoke mixture container 
coatings, 110-112 

p-Chloro-m-xylenol, as leather dis¬ 
infectant, 141 







INDEX 


211 


Clay filtering of petroleum base 
stocks for contamination re¬ 
moval, 7 

Cleaning of gasoline containers for 
use in transporting drinking 
water, 116 

Climatic operability of ordnance 
equipment extended by im¬ 
proved hydraulic fluids, 2 
Clothing, water repellent; see Wa¬ 
ter repellent finishes for fa¬ 
brics 

Cloud point of hydraulic fluids, 9 
CM, flame retardant efficiency, 161 
Coal tar pitch, resistance to bac¬ 
teria, 107 

Coal-dust spray technique for oxy¬ 
gen mask testing, 50 
Coated fabrics for quartermaster, 
uses, 172 

Coatings, anticorrosive for Navy 
vessels; adhesion, 92-93 
antifouling coatings, 92, 97-102 
bacteria as cause of corrosion, 92, 
104-107 

blistering, 94-96 

chemical paint removers, 92, 102- 
103 

copper leaching tests, 98-99 
corrosion, 93-94, 104-107 
electrical resistance as measure 
of coating deterioration, 92, 
96-97 

fire-retardant paints, 92, 107-109 
mechanical cleaning methods, 
103-105 

permeability of ions, 95 
primers, 93-94 
surface preparation, 93-94 
Coatings, rust inhibiting, for met¬ 
als, 164-165 

Cohesive energy density of poly¬ 
vinyl chloride, 170 
Cold cracking test for leather sub¬ 
stitutes, 138 

Coleoptera, damage to Quartermas¬ 
ter items, 149 

Color-changing paste markers for 
front line identification, 37-40 
Colored flares, 22-23 
effect of air absorption of light on 
apparent color, 22 
effect of sodium salts on color 
purity, 22 

formulas for red, yellow, white, 
and green flares, 23 
need for truly monochromatic 
flare, 22-23 
requirements, 22 


Color-temperature measurements of 
photoflash bombs, 28 
Combat course tests, wear resist¬ 
ance of apparel fabrics, 173- 
175 

Combat rations, solid fuels for 
heating, 156-159 
Compass fluids, 2, 7 
Compatibility constant, polymer 
liquid systems, 169 
Compressed air, use in low tem¬ 
perature inflation of life 
rafts, 34 

Condenser for solar still, 89 
Conjulin as tung oil substitute, 164 
Copper leaching tests of antifouling 
coatings, 98-99 

Copper regenerative unit for fuel 
tank explosion prevention, 
16-17 

Copper surface preparation for 
good paint adherence, 94 
Cordite, research recommendation 
for high pressure gas gen¬ 
erator, 76 

Cork substitutes, wool waste for 
shell casing plugs, 119 
Corrosion; bacterial effects on met¬ 
al corrosion, 104-107 
comparison of corrosion rates in 
sea water and sediments, 107 
effect of chemical changes in sea 
water on paint films, 93-94 
relationship of sulfate reducing 
bacteria for corrosion proc¬ 
ess, 105 

Corrosion resistant coatings and 
linings; adhesion, 101 
antifouling coatings for ship bot¬ 
toms, 97-102 

application methods, 111-112 
binder, 101 

for chemical munitions, 110-112 
for fuel and lubricant containers, 
112-113 

P-10 primer, 102 
sealing of Navy primers and 
fuzes, 113-115 
WP-1 wash primer, 102 
Cowling skimmers for dust removal 
from air ducts; advantages, 
15 

cleanup efficiency, 15 
principle of operation, 14 
Creep characteristics of plastic 
films; effect of plasticizer 
composition, 168 
effect of resin composition, 168 
experimental procedure, 168 
theoretical discussion, 168 


Crosslinking; effect of ultraviolet 
light, 171 

effect on second order transition 
points in high polymers, 167 
Crotonaldehyde for lubricating oil 
sabotage, 87 

Crucible, Acheson graphite, for 
fusion of magnesium fluor¬ 
ide, 118 

Crude oils, base stocks for hydrau¬ 
lic fluids; removal of aroma¬ 
tic hydrocarbons, 7 
use of naphthenic crudes, 7 
Cyclic ethylene trithiocarbonate, as 
nonvolatile cosolvent for 
HP, 64 

Cyclohexanone; 

as paint remover, 102 
solvent action on vinyl resins, 169, 
170 

Cyclohexylamine as paint remover, 
102 

Damping fluids for fire-control 
equipment, 2, 7-8 

Deacidite for removing salt from 
sea water, 88 

Dearomatization of petroleum base 
stock, 7 

Deformation test for leather sub¬ 
stitutes, 138 

Degradation of vinyl and diene 
polymers, 170 

Deleading of gasoline, 143-144 
Dermaptera, damage to Quarter¬ 
master items, 149 
Desulfovibrio, sulfate-reducing bac¬ 
teria, 105 

Detergents, effect on water repell¬ 
ent fabrics, 146 

Devoe-Raynolds paint remover, 102 
Dewaxing of petroleum base stock, 
6-7 

Diammonium hydrogen phosphate 
as flameproofing agent, 163 
Dibasic acid esters for noninflam¬ 
mable hydraulic fluids, 12 
Dichloroethylene as paint remover, 
102 

1,1-Dichloro-l-nitroethane as pro¬ 
knock, 85 

Diffusion constant, water vapor 
permeability of plastic films, 
167 

Dilution ratio measurements, poly¬ 
vinyl resin solutions, 170 
Dimethoxy tetra-ethylene glycol for 
noninflammable hydraulic 
fluids, 12 

Dioxane, solvent action on vinyl 
resins, 169 








212 


INDEX 


Dipping process of plastic films for 
packaging, 178-181 
Diptera, damage to Quartermaster 
items, 149 

Distillation of drinking water from 
sea water; solar stills, 89-90 
vapor compression still, 91 
Dow Chemical Company, 16 
Dowty piston, 6 

Drinking water, cleaners for gaso¬ 
line containers to be used for 
water transportation, 116 
Drinking water, production from 
sea water; chemical methods, 
88, 89 

double-effect evaporators, 88 
electrolyte method, 88 
solar stills, 89-91 
vapor compression still, 91 
Drop-penetration test for water re¬ 
pellent fabrics, 145-149 
DTD-585 hydraulic fluid, 7, 10 
Duct skimmer for dust removal 
from air ducts, 14 
du Pont CM as flameproofing agent, 
163 

du Pont GF-35 oil as tung oil sub¬ 
stitute, 164, 165 

du Pont rain tester for water re¬ 
pellent fabric, 146 
du Pont T as flameproofing agent, 
163 

du Pont 3-WG as flameproofing 
agent, 163 

Dura-Lana shrinkproofing process, 
176 

Dust removal from aircraft engine 
air supply, 14-15 
channel air filter, 14 
cowling skimmer, 14-15 
dust skimmer, 14 

Dust suppression around artillery 
emplacements, 127-131 
blast mats, 129-131 
chemical treatment of ground, 
127-129 

Dye marker for plane crash loca¬ 
tion, 47-48 

control of solution rate, 47 
dye composition, 47 
releasing mechanism, 48 
requirements, 47 

Dyes for use in front line marker, 
37-40 

84 primer, 92, 95, 108-109 
Elastomers, molecular model for 
consideration of transition 
phenomena, 167 


Electrical resistance of coating as a 
measure of deterioration, 96- 
98 

Electrolytic methods; deposition of 
sea water salts on steel as 
anticorrosive coating, 113 
drinking water produced from 
sea water, 88 
metal cleaning, 103 
Electrometer for use in corrosion 
measurements of paint films, 
96 

Elektrochemisches Werke Munchen, 
133 

Ellicote P-1, flame retardant effi¬ 
ciency, 161 

Embioptera, damage to Quarter¬ 
master items, 149 

Engines, gasoline, effect of gasoline 
sabotage, 85-86 

Entropy, of dilution, polymer-liquid 
systems, 168 

Enzyme shrinkproofing process, 177 
Ephemeroptera, damage to Quar¬ 
termaster items, 149 
/?-(methoxy-methoxy) Ethanol for 
noninflammable hydraulic 
fluids, 12 

Ethyl thionitrite, use as proknock, 
85 

Ethylene dichloride, use as paint 
remover, 102 

Ethylene glycol for noninflammable 
hydraulic fluids, 12 
2-Ethylhexyl nitrite chloropicrin, 
use as proknock, 85 
2-Ethylhexyl sebacate; for nonin¬ 
flammable hydraulic fluids, 
12 

in damping fluids, 8 
Evaporator for solar still, 89 
Exchange resins for use in prepar¬ 
ing drinking water from sea 
water, 88-89 

Exercise, effect on respiration 
rates, 78 

Exhaust gas system for fuel tank 
explosion prevention, 17-19 
flame arrester, 19 
flight tests, 17-19 
ground tests, 17 
heat exchanger, 18 
pressure relief valve, 19 
Expiratory resistance, 79-80 
Explosion protection of aircraft 
fuel tanks, 16-19 
activated carbon burner, 16 
copper regenerative unit, 16 
hazardous temperature range for 
aviation gasoline, 16 
inert exhaust gas system, 17-19 


Explosive photoflash powder, 24 

F-142 hot plastic antifouling coat¬ 
ing, 98 

Fabrics, apparel, abrasion resist¬ 
ance, 174-175 

Falkwood, as tung oil substitute, 
164 

Felting of wool, shrinkproofing pro¬ 
cesses for prevention of; see 
Shrinkproofing 

Ferrosilicon-caustic system of hy¬ 
drogen production for mete¬ 
orological balloons, 41-42 
cu. ft. of hydrogen per lb., 41 
disadvantages, 41 

15 R. C. antifouling coating, 98 

52P22 paint, fire retardant proper¬ 
ties, 109 

Films, plastic; for packaging, 178- 
179 

viscoelastic properties, 167-168 
viscosity-temperature character¬ 
istics, 178 

water vapor permeability, 167, 
180-181 

Filters for dust removal from air 
ducts; channel air filter, 14 
cowling skimmer, 14-15 
dust skimmer, 14 
fabric and metal cloth filters, 40 

Fire control equipment, hydraulic 
fluids, 1-2 

Fire hazards, storage of chlorinated 
lime, 183 

Fire point of hydraulic fluids, 9 

Fire retardant paints, 107-109 

Fire retardants for textile flame¬ 
proofing; see Flameproofing 
of textiles 

Flame arrester for fuel tank explo¬ 
sion prevention system, 19 

Flame method of metal cleaning, 
103 

Flame throwers, portable, high 
pressure hydrogen generator, 
72 

Flameproofing of textiles, 160-163 
chemical and physical properties 
of flameproofing agents, 162 
commercial retardants and fin¬ 
ished fabrics, 161 
effect of traces of fire retardants 
remaining after leaching, 
161-162 

evaluation of water soluble fire 
retardants, 160 

insulation value of flameproofed 
fabrics, 162 

rates of degradation of flame- 
proofed fabrics, 162 




INDEX 


213 


test methods, 160-161 
thermal decomposition of cellu¬ 
lose, 161 

urea-phosphate flameproofing, 162 
volatile decomposition, 161 
Flamex, flame retardant efficiency, 
161 

Flamort T. C., flame retardant effi¬ 
ciency, 161 
Flares, 20-23 

colored flares, 22-23 
efficiency, 20 
ignition problems, 20 
light measurement technique, 20 
No. 47 flare mixture, 21 
rocket star, 21-23 
underwater flare, 20-21 
Flash point of hydraulic fluids, 6, 
8, 9, 12 

Flash powders; explosive, 24 
non-explosive, 25 

Flashing tendency of paints as fire 
hazard, 318 

Flexibility measurement at low tem¬ 
peratures of plastic films for 
ration packaging, 180 
Flex-pressure test for leather sub¬ 
stitutes, 138 

Flory-Rehner equation, 170 
Flow meter for instantaneous air¬ 
flow measurements, 77 
Fluidized powder techniques for 
production of hydrogen per¬ 
oxide, 135-137 

FM (titanium tetrachloride) con¬ 
tainer coatings, 110-112 
Folding endurance of films and 
coated fabrics, 172 
Food cans, baked exterior finishes, 
164-166 

Fouling prevention, ships bottoms; 

see Antifouling coatings 
47 flare mixtures, 21 
Fractional melting purification pro¬ 
cess for Levinstein H, 54 
Fractionation of vinyl resin solu¬ 
tions, 169 

Frazier-Nash turret, hydraulic 
fluid tests, 10 

Freney-Lipson shrinkproofing pro¬ 
cess, 177 

Front line identification by vanish¬ 
ing markers, 37-40 
FS smoke mixture; container coat¬ 
ings, 110-112 
use as proknock, 85 
Fuel containers; anticorrosive lin¬ 
ings, 112-113 

cleaning methods for use in trans¬ 
porting drinking water, 116 


surface preparation for linings, 

112- 113 

Fuel tank explosions, protection 
against, 16-19 

activated carbon burner, 16-17 
hazardous temperature range for 
aviation gasoline, 16 
inert exhaust gas system, 17-19 
Fuels for heating combat rations, 
156-159 

carbonaceous fuels, 158-159 
carbowax, 157 
trioxane, 156, 157 
Full-face oxygen mask, 51-52 
Fungus resistance of plastic hot 
melts for ration packaging, 
181 

Furfural for flare mixture binder, 
21 

Furfuryl alcohol for lubricating oil 
sabotage, 87 

Fuzes, corrosion-resistant coatings, 

113- 114 

Galvanized iron, surface prepara¬ 
tion for paint adherence, 94 
Gas masks; canister charcoal ac¬ 
ceptance tests, 78 
inspiratory and expiratory valves, 
80-81 

maximum allowable respiratory 
resistance, 80-82 
research recommendations, 83 
respiratory resistance limit, 82 
subjective reactions, 82 
Gaskets in hydraulic systems, effect 
of hydraulic fluids, 8 
Gasoline; deleading methods, 143 
sabotage by addition of oil solu¬ 
ble phenolic resins, 85-86 
Gasoline containers; anticorrosive 
linings, 112-113 

cleaning methods for transporting 
drinking water, 116 
surface preparations for linings, 
112-113 

Gasoline tank explosions, protection 
against, 16-19 

activated carbon burner, 16-17 
hazardous temperature range for 
aviation gasoline, 16 
inert exhaust gas system, 17-19 
Gasoline-air mixtures as explosion 
hazard, 16-19 

Gels, thixotropic, formed by acrylic 
acid polymers at low temper¬ 
atures, 4 

General Dyestuff Co. dyes, 38 
General Foods moisture-vapor 
transmission cabinet, 178 



Geon 101, molecular weight, 169 
Geon 202, molecular weight, 169 
GF-35 for water can coatings, 166 
Glass bottles for photoflash bomb 
casings, 24 

Glow discharge process for produc¬ 
tion of concentrated hydro¬ 
gen peroxide, 133 

Glow retardants, kinetics of the 
oxidations of carbon, 163 
Glyoxal-resorcinol tannages, re¬ 
sistance to alkaline detanni- 
zation, 141 

Glyptal coatings, permeability to 
ions, 95 

Green AB dye for use in front line 
marker, 38 
Green flares, 22-23 
Guided missiles, colored flares for 
tracking, 20, 22-23 
Gunner munitions, uses of hydrogen 
peroxide, 132 

Gypsum plaster for treatment of 
soil for dust suppression, 128- 
129 

H, Levinstein process mustard gas; 
see Levinstein H mustard 
gas 

Halogenated hydrocarbons for non- 
inflammable hydraulic fluids, 
12 

Halogenation shrinkproofing pro¬ 
cesses, 176 

Halowax, resistance to bacteria, 107 
HD, distilled Levinstein H; see Lev¬ 
instein H 

Heat ageing of high polymers; poly¬ 
vinyl chloride, 171 
synthetic rubbers, 171 
Heat exchanger for fuel tank ex¬ 
plosion prevention system, 18 
Heat of dilution, polymer-liquid sys¬ 
tems, 168 

Helmet technique for oxygen mask 
testing, 50 

Herringbone twill, wear resistance, 
173-175 

Hexamethylene tetramine; as a 
stabilizer for Levinstein H, 
59 

in pentane detarring process, 56 
in preparation of thickened H, 59 
in steam distillation process for 
mustard gas purification, 55 
Heyden 395 oil as tung oil substi¬ 
tute, 164 

High polymers; heat and light ag¬ 
ing, 170-172 





214 


INDEX 


molecular model for considera¬ 
tion of transition phenomena, 
167 

High speed motion picture studies 
of photofinish bombs, 28-31 
Hot air jet method of lip setting, 
for Army shoe insoles, 139- 
140 

HP, mustard gas modification; cel¬ 
lulose sponge as an absorb¬ 
ent, 64 

effect of addition of white phos¬ 
phorous, 63-64 
Hs-293 glide bomb, 132 
HV, thickened Levinstein H mus¬ 
tard gas; see Levinstein H 
Hycon piston, 6 
Hydraulic fluids, 1-13 
blending procedure, 9 
centistoke viscosity, 8-9 
cloud point, 9 
compass fluids, 7-8 
damping fluids for fire control and 
directional equipment, 7-8 
effect of excessive turbulence un¬ 
der high pressure drop con¬ 
ditions, 5-6 

effect on rubber gaskets, 8 
fire point, 9 
flash point, 6, 9 
improved hydraulic fluids, 7 
inflammability, 11-12 
loss of viscosity due to shear, 5-6 
military requirements, 1-6 
petroleum base stocks, 6-7 
pour point, 6, 9 
prevention of tacky residue, 8 
research recommendations, 12-13 
service tests, 5-7, 10-11 
specifications, 8-9 
use of polymeric additives, 3-6 
viscosity index, 9 
viscosity-temperature character¬ 
istics, 1-4, 8-10, 12 
Hydro-blast wet sandblasting clean¬ 
ing equipment, 104 
Hydrocarbon base hydraulic fluids; 

see Hydraulic fluids 
Hydrogen, chemical sources; cal¬ 
cium hydride, 45 

ferrosilicon and caustic sodas, 41, 
42 

hydrogen generator for filling 
meteorological balloons, 43-45 
lithium hydride, 41-44, 142 
sodium borohydride, 45-46 
sodium hydride-aluminum mix¬ 
tures, 43-45 


Hydrogen generator for pressuriz¬ 
ing portable flame throwers, 
72-76 

breech plug cup, 75 
comparison with conventional sys¬ 
tems, 74 

cooling requirements, 75 
cyclone separator, 76 
lithium hydride cartridge, 72, 75 
operation, 72-74 
pressure tests, 76 
ratio of water to hydride, 75 
recommended air-cooled units, 76 
research recommendations for 
cordite generator, 76 
water feed time, 75 
Hydrogen peroxide; application of 
fluidized powder techniques 
to the barium production 
process, 135-137 

cyclic reduction and oxidation of 
2-ethylanthraquinone 134-135 
glow discharge production pro¬ 
cess, 133-134 

photochemical synthesis, 134 
pilot plants for distillation pro¬ 
cess, 132-133 
uses in munitions, 132 
Hydrostone for treatment of soil 
for dust suppression, 128-129 
Hygroscopicity of chlorinated lime 
and calcium hypochlorite, 184 
Hymenoptera, damage to Quarter¬ 
master items, 149 
Hypol shrinkproofing process, 176 

Identification markers, vanishing, 
37-40 

Ignition of star mixtures and flares; 
matches for low temperature 
operations, 23 
priming system, 23 
Impact methods for metal cleaning; 
Aurand paint removal tool, 
103-104 

wet sandblasting, 103-104 
Indigoid dyes used in front line 
marker, 38 

Induction furnace, Ajax 3P2; 118 
Inert exhaust gas system for fuel 
tank explosion prevention, 
17-19 

flame arrester, 19 
flight tests, 17-19 
ground tests, 17 
heat exchanger, 18 
pressure relief valve, 19 
Inflammability of hydraulic fluids, 
11-12 

avoidable service losses, 11-12 


hydrocarbon base fluids, 11-12 
silicon oil base fluids, 12 
Inflation of life rafts at low tem¬ 
peratures; see Life rafts, 
low temperature inflation 
Insect damage to Quartermaster 
items, 148-150 
control methods, 149 
recommendations, 149-150 
Insoles of Army shoes; cause of de¬ 
terioration, 142 

hot-air jet method of lip setting, 
139-140 

Inspiratory air-flow; effect of 
amount of work performed, 
77-79 

effect of inspiratory resistance, 

78 

effect of strenuous exercise, 78, 

79 

effect of tropical environment, 78 
effect of weight carried, 78 
field studies, 82 

length of inspiratory and expira¬ 
tory cycles, 77 
maximum flow rates, 77-80 
minute volumes, 77-79 
research recommendations, 83 
Instantaneous respiration rates; 
see Respiration rates, instan¬ 
taneous 

Isoamyl nitrite, as proknock, 85 
Isobutylene, polymerized, in hy¬ 
draulic fluids, 4 

Isoptera, damage to Quartermaster 
items, 149 

Japanese army service mask, 80 

K oil for water can coating, 166 
Kelgum, 128 

Kellin as tung oil substitute, 164, 
166 

Keltex, 128 

Kem-Tone, fire retardant proper¬ 
ties, 109 

Kidde safety head used on high 
pressure hydrogen generator, 
76 

L-12 mask oxygen mask, 50-51 
leakage tests, 51 

Lana-Seal shrinkproofing process, 
176 

Lanaset shrinkproofing process, 176 
Landing gears, hydraulic fluids for, 
1 

Laporte, Ltd., 132 
Laundering, effect on water repel¬ 
lent fabrics, 146 





INDEX 


215 


Leaching rate measurements on an¬ 
tifouling coatings, 98-99 
correlation with fouling resist¬ 
ance, 99 

measurement technique, 98-99 
theories of fouling prevention, 98- 
99 

Leakage in hydraulic systems, vis¬ 
cosity requirements of hy¬ 
draulic fluids, 2 

Leakage tests, oxygen masks; coal 
dust spray technique, 50 
helmet technique, 50 
valve leakage test, 80 
Leather; mold resistance, 141 
special protective treatments, 141- 
142 

synthetic tanning agents, 141 
Leather substitutes; adhesives, 139- 
140 

for shoes, 138-139 
standard laboratory tests, 138 
Lens coatings, preparation of mag¬ 
nesium fluoride, 117-118 
Lepidoptera, damage to Quarter¬ 
master items, 149 

Leuco form of dyes used in front 
line marker, 38 

Levinstein H mustard gas, 53-64, 
110 

addition of white phosphorous to 
increase volatility, 54, 63-64 
chemical nature, 62 
container coatings for prevention 
of deterioration, 110-112 
effectiveness against troops, 60-61 
evaporation in high altitude 
spray, 53 

fractional melting, 54 
freezing point, 54 
limitations, 62-63 
optimum drop size for aircraft 
spray, 53 

penetration of fabric, 62 
pentane detarring, 55-56 
pentane extraction, 55-56 
preparation of thickened H, 53, 
56-59 

pressure stability of crude and 
purified H, 53 
purification, 54-56 
rate of evaporation formula, 60- 
61 

stability of thickened H, 59-61 
steam distillation, 55 
tactical use, 61-62 
vacuum distillation, 56 
Lewisite; container coating for pre¬ 
vention of deterioration, 110- 
112 


plants for vacuum distillation of 
Levinstein H, 56 

Life rafts, folded solar still for 
drinking water production, 
90 

Life rafts, low-temperature infla¬ 
tion, 32, 33 

carbon dioxide inflation system, 
32, 33 

cylinder dip pipe, 35 
disadvantages of heating storage 
compartments, 36 
nitrogen and carbon dioxide mix¬ 
tures, 34 

redesign of valve manifold sys¬ 
tem, 34-35 

research recommendation for 
chemically heated cylinder, 
36 

use of compressed air, 34 
use of nitrous oxide, 34 

Light aging of high polymers, 170- 
171 

effect of ultraviolet light, 171 
evaluation of light sources, 171 
synthetic rubbers, 171 

Light measurement techniques; use 
of filtered barrier-type photo¬ 
cell to give measurement in 
eye units, 20 

Light measurements; see Optical 
measurements 

Light scattering technique for 
molecular weight measure¬ 
ments, 169 

Linings, corrosion resistant; see 
Corrosion resistant linings 
and coatings 

Lip-setting of oil treated insoles in 
Army shoes, 139-140 

Liquid filled shells, exterior ballis¬ 
tics, 65-70 

comparison of liquid and solid 
filled shells, 65-66 
critical speed of liquid filled top, 
66-67 

effect of internal vanes, 65-68 
effect of muzzle velocity, 68 
effect of rifling pitch, 68 
effect of viscosity of liquid, 66, 68 
effect of void spaces, 66-67 
experiments with liquid filled top, 
66-68 

laboratory ballistics testing ma¬ 
chine, 68-70 

Milne criteria of stability, 66 
model studies, 68 
stability factor, solid spinning 
projectiles, 65-66 


Lithium; electrolytic production 
process, 41, 42 

produced by reduction of spodu- 
mene under vacuum, 42-43 
Lithium hydride; as source of hy¬ 
drogen for meteorological 
balloons, 41-43 

use in hydrogen generator for 
pressurizing portable flame 
throwers, 72, 75 

Low temperature inflation of life 
rafts; see Life rafts, low tem¬ 
perature inflation 
Lubricating oil sabotage, 86-87 

M2-2 portable flame throwers; hy¬ 
draulic fluids, 1 repressuriz¬ 
ing requirements, 74 
Magnesium coatings, electrical re¬ 
sistance as measure of cor¬ 
rosion resistance, 96-97 
Magnesium fluoride; analysis of 
commercial fluoride, 118 
preparation for use as lens coat¬ 
ing, 117-118 

Mare Island plastic No. F-142, dis¬ 
advantages as antifouling 
coatings, 97 

Mark 28 fuzes, corrosion-resistant 
coatings, 114 

Markers, plane crash location; see 
Dye marker, plane crash lo¬ 
cation 

Markers, vanishing, for front line 
identification in jungle, 37-40 
covering power, 39 
paste type marker, 37-39 
powder type markers, 39-40 
recommendations for parachute 
type marker, 39 

reflectance as function of devel¬ 
opment time, 39 

Masks, protective respiratory; see 
Gas masks, Oxygen masks 
Matches for low temperature opera¬ 
tion in flare ignition systems, 
23 

Me-163 jet-propelled aircraft, 132 
Mesityl oxide; as paint remover, 102 
in sabotaging lubricating oil, 86 
Metal cleaning, 102-104 
abrasive methods, 103 
Aurand paint removal tool, 103- 
104 

chemical paint removers, 102 
electrolytic method, 103 
flame method, 103 
mechanical cleaning methods, 103- 
104 

wet sandblasting, 103-104 




216 


INDEX 


Metarrhizium glutinosum, resist¬ 
ance of plastic hot melts, 181 
Meteorological balloons, chemical 
sources of hydrogen for, 41- 
46 

generator for filling balloons, 43- 
44 

Methyl carbitol for noninflammable 
hydraulic fluids, 12 
Methyl ethyl ketone, solvent action 
on vinyl resins, 169 
Methyl methacrylate as thickener 
for mustard gas solutions, 
57-59 

Methylene chloride, use as paint re¬ 
mover, 102 

Microspira, sulfate-reducing bac¬ 
teria, 105 

Midsoles, Army shoes; adhesives, 
139-140 

leather substitutes, 139 
prevention of shrinkage, 142 
Mites, damage to Quartermaster 
items, 149 

Moisture vapor permeability of 
plastic films, 167,180-181 
Mold resistance of leathers, 141 
Molecular weight; acryloid polym¬ 
ers, 4-6 

distribution curves for Vinylite 
VYNW and Geon 101; 169 
effect on second order transition 
points in high polymers, 167 
techniques of measurement, 169- 
170 

Montgomery Bros, treated fabric, 
flame retardant efficiency, 
161 

Morpholine paint remover, 102 
Motor vehicles; gasoline sabotage, 
85-86 

lubricating oil sabotage, 86-87 
MSA self-contained oxygen appa¬ 
ratus, 49-50 

Mustard gas; see Levinstein H mus¬ 
tard gas 

Muzzle velocity, effect on projectile 
stability, 68 

Naphthenic crude oils for use in hy¬ 
draulic fluids, 7 
National Anilinine, 38 
Navy white long and short oxygen 
masks, 49 

Neoprene blast mats for dust sup¬ 
pression around artillery em¬ 
placements, 130 

Neutronyx shrinkproofing process, 
176 


Nitrogen chloride, use of proknock, 
85 

p-Nitrophenol as leather disinfect¬ 
ant, 141 

Nitrosyl chlorides, use as proknock, 
85 

Nitrous oxide used for life raft in¬ 
flation at low temperature, 
34 

Nonexplosive flash powders, 25-26 
Non-hydrocarbon base hydraulic 
fluids, 11-12 

ethylene glycol-water mixtures, 12 
silicone oils, 12 

Noninflammable hydraulic fluids, 
11-12 

avoidable service losses due to 
inflammability of existing hy¬ 
draulic fluids, 11 

ethylene glycol-water mixtures, 
12 

silicone oils, 12 

Nylon blast mats for dust suppres¬ 
sion around artillery em¬ 
placements, 129 

Oil spills, treated sand for use in 
removal from harbors, 121 
Oils, recoil; see Hydraulic fluids 
Oil-soluble polymeric additives for 
hydraulic fluids, 3-5 
Optical measurements; high-speed 
photography for flash studies, 
28-31 

oscillographic flash photometry, 
27 

photographic flash photometry, 26 
spectographic flash studies, 27-28 
use of filtered barrier type photo¬ 
cell to give measurements in 
eye units, 20 
Orange R dye, 38 

Ordnance equipment, hydraulic flu¬ 
ids; see Hydraulic fluids 
Ordnance plugs, wool waste as cork 
substitute, 119 

Organic coatings for metals, 164- 
165 

for food cans, 165-166 
for water cans, 166 
tung oil substitutes, 164-166 
Orthoptera, damage to Quartermas¬ 
ter items, 149 

O.S.-1113 specification for hydraulic 
oil, 7, 11 

O.S.-1433 specifications for anti¬ 
corrosive coating, 114 
O.S.-2943 specification for hydraulic 
oil, 7, 9, 11 


Oscillograph photometer for photo¬ 
flash bomb measurements, 27 
Osmometers for molecular weight 
determination, 169 
Osmotic pressure technique for 
molecular measurements, 
169-170 

Outsoles for Army shoes; adhesives, 
139-140 

GRS substitutes, 139 
Oxidation rate of high polymers; 
effect of antioxidants, 171 
effect of chemical structure, 171 
effect of vulcanization, 171 
synthetic rubbers, 171 
Oxygen consumption, correlation 
with pulse rate, 82 
Oxygen deficit respiration rate, 82 
Oxygen masks, valve characteris¬ 
tics, 80-81 

Oxygen masks for high-altitude 
low-temperature use, 49-52 
defects of MSA oxygen appara¬ 
tus, 50 

disadvantages of MSA and BLB 
masks, 49-50 
full face mask, 51-52 
L-12 oxygen mask, 50-51 
requirements, 49 
test methods, 50 

Ozone attack, degradation of syn¬ 
thetic rubbers, 171 

P-10 primer, anticorrosive coating, 
102 

Packaging with plastic films, 178- 
181 

blocking tests, 179 
desirable properties, 178-179 
handling tests, 179-180 
moisture-vapor permeability test, 
180, 181 

viscosity-temperature tests, 179 
Paint removal, 102-104 
abrasive methods, 103 
Aurand paint removal tool, 103- 
104 

chemical paint removers, 102 
electrolytic method, 103 
flame method, 103 
mechanical cleaning methods, 
103-104 

wet sandblasting, 103-104 
Paints, anticorrosion; adhesion, 93, 
94 

blistering, 94-96 
corrosion, 93-94 
effect of bacteria, 107 
for ship bottoms, 92-109 
moisture resistance, 92-93 



INDEX 


217 


resistance to weak alkalies, 93 
temperature stability, 94 
Paints, fire retardant, 107-109 
blistering as fire hazard, 108 
effect of pigment-to-binder ratio, 
107, 108 

modification of Navy 84 primer, 
108-109 

paint formulations, 109 
tendency to flash, 108 
test apparatus, 108 
thickness of paint layer principal 
cause of hazard, 107 
white paint No. 29, 109 
Parachute markers, research rec¬ 
ommendation, 40 

Paradura, oil soluble phenolic resin 
for gasoline sabotage, 86 
Paramet Chemical Corporation, 86 
Paramine hydrochloride for “dop¬ 
ing” oil-sinking sand, 121 
Parlon-X, as sealing compound for 
delay-element primers, 115 
Peeling of anticorrosive paint films, 
94-95 

Pentane, purification processes for 
Levinstein H, 54-56 
Perbunan-coated nylon blast mats 
for dust suppression around 
artillery emplacements, 130 
Permeability to moisture vapor per¬ 
meability of plastic films, 
167, 180-181 

Peroxide drive for submarines and 
torpedoes, 132 

Perspiration, influence on insole 
leathers, 142 

Petroleum base stocks for hydraulic 
fluids, 3, 6-7 

clay filtering and blotter press¬ 
ing, 7 

dewaxing, 7 

distillation to produce required 
viscosity and volatility, 7 
use of naphthenic crudes, 7 
Petroleum wax substitutes for 
packaging uses, 178-181 
pH, relationship to stability of 
chlorinated lime, 184 
Phenolic resin films; for anti-cor¬ 
rosive coatings for fuel con¬ 
tainers, 112-113 

for linings for chemical muni¬ 
tions, 110-112 
permeability to ions, 95 
Philadelphia Quartz Company D 
Brand sodium silicate, 128 
Phosphamates, flame retardant ef¬ 
ficiency, 161 


Phosphorus, white, added to mus- 
stard gas to increase vola¬ 
tility, 63 

Phosphorus dichloronitride for gas¬ 
oline sabotage, 86 

Phosphorus sulfochloride, use of 
proknock, 85 

Phosphorus trichloride; for gaso¬ 
line sabotage, 86 
use of proknock, 85 
Photo oxidation of synthetic rub¬ 
bers, 171 

Photocell, barrier-type, with filter, 
for light intensity measure¬ 
ments in eye units, 20 
Photocell and oscillograph photo¬ 
meter for photoflash bomb 
measurements, 27 

Photochemical synthesis of concen¬ 
trated hydrogen peroxide, 
134 

Photoflash bombs; analysis of 

faulty flashes, 30-31 
casings, 24-25 
explosive powder, 24, 25 
flash efficiency, 28-30 
high speed motion picture stud¬ 
ies, 28-31 

M-46 photoflash bomb, 24 
non-explosive powders, 25-26 
photocell and oscillograph method 
of flash photometry, 27 
photographic flash photometry, 
26 

spectrographic studies, 27-28 
Photographic flash photometry, 26 
Photometric studies of photoflash 
bombs; high speed motion 
picture method, 28-31 
oscillograph and photocell meth¬ 
od, 27 

photographic method, 26 
Pink IREX dye, 38 
Pink R dye, 38 

Pipe line corrosion, factors respon¬ 
sible for, 104 

Plane crash dye marker, 47-48 
Plastic, hot, antifouling coatings, 
97-98 

Plastic films; for packaging, 178- 
179 

measurement of flexibility char¬ 
acteristics, 180 

viscoelastic properties, 167-168 
viscosity temperature character¬ 
istics, 178 

water vapor permeability, 167, 
180-181 



Plasticization; effect on second or¬ 
der transition paints in high 
polymers, 167 

effect on water vapor permeabil¬ 
ity of plastic films, 167 
Plasticizers, effect on composition 
on creep behavior of Vinylite 
VYNW, 168 

Plugs, ordnance, wool waste as cork 
substitute, 119 

Pollack fabric, flame retardant ef- 
fiency, 161 

Polybutene for hydraulic fluids, 4, 
10 

Polyglycol-mixed ethers for non- 
inflammable hydraulic fluids, 
12 

Polymeric additives; for hydraulic 
fluids, 3-5, 7-8 

for thickening Levinstein H and 
other vesicant sprays, 56-57 
Polymer-liquid systems, theory, 
168-170 

swelling measurements for de¬ 
termination of polymer-sol¬ 
vent interaction, 170 
Polystyrene; effect on degradation 
of high polymers, 170 
permeability to ions, 95 
Polyvinyl alcohol as seaming com¬ 
pound for vesicant-carrying 
munitions, 111 

Polyvinyl butyral; corrosion of 
resin-coated panels, 95 
effect of resin composition on 
creep characteristics, 168 
for binder in antifouling coat¬ 
ings, 101 

permeability to ions, 95 
Polyvinyl chloride; ability to form 
associated clusters in diox- 
ane solution, 169 
heat and light aging, 171 
Potable water, production from sea 
water; chemical methods, 
88-89 

double-effect evaporators, 88 
electrolytic method, 88 
solar stills, 89-91 
vapor compression still, 91 
Pour point of hydraulic fluids, 6, 9 
Powder, photoflash, 24 
optimum confinement, 25 
Powder K oil, Atlas, 164 
Pressure stability of crude and 
purified Levinstein H, 53 
Pressure tanks of portable flame 
throwers, high pressure hy¬ 
drogen generator, 72-76 




218 


INDEX 


Priming coat, anti-corrosive paint; 
blistering, 94-96 
corrosion, 93-94 
No. 84 primer, 92, 95, 108-109 
surface preparation, 93-94 
Priming system for flare ignition, 
23 

PRL 1700 damping fluid, 8 
PRL 1866 damping fluid, 8 
PRL-Ac-239 damping fluid, 8 
Projectiles, liquid-filled, 66-68 
Proknocks, 84-85 

disadvantages of dispersal on 
enemy fields to prevent 
plane take-offs, 85 
effectiveness, 85 
for automobile engines, 85 
Protective respiratory equipment; 
see Gas masks; Oxygen 
masks 

Propylene dichloride, use as paint 
remover, 102 

Propylene glycol for noninflamma¬ 
ble hydraulic fluids, 12 
Psocoptera, damage to Quarter¬ 
master items, 149 

Pulse rate, correlation with oxygen 
consumption, 82 

Pump tests of hydraulic fluids, 5 
Purification of Levinstein H mus¬ 
tard gas, 54-56 
fractional melting, 54 
pentane detarring, 55-56 
pentane distillation, 54 
pentane extraction, 55-56 
steam distillation, 55 
vacuum distillation, 56 
Pyrotechnics; flares, 20-23 
photoflash bombs, 24-31 
Pyrox paint remover, 102 

Ration packaging, use of plastic 
films, 178-181 

RCA 919 cesium oxide photoelectric 
cell used in oscillographic 
flash photometer, 27 
Rebreathing devices, protective res¬ 
piratory equipment, 82 
Recoil oils; see Hydraulic fluids 
Recommendations for future re¬ 
search; chemically heated 
cylinder for life raft infla¬ 
tion system, 36 

electrically heated catalyst for 
use in fuel tank explosion 
prevention system, 19 
high intensity flash bombs, 26 
high pressure gas generator 
based on burning of cordite, 
76 


hydraulic fluids, 12 
mechanical reduction of the peak 
flow of air in gas masks, 83 
nonexplosive flash powders, 25 
parachute markers for front line 
identification, 40 

resistance of uncoated mag¬ 
nesium partially submersed 
in sea water, 97 

Reconnaisance photographs, use of 
photo-flash bomb, 24 
Red flares, 22-23 
Red violet RH dye, 38 
Reflectance of front line marker 
paste, 39 

Rescue aids, plane crash dye mark¬ 
er, 47-48 

Research recommendations; see 
Recommendations for future 
research 

Resin composition, effect on creep 
characteristics of plasti¬ 
cized vinyl films, 168 
Resin shrinkproofing processes, 176 
Resistance, electrical, as measure 
of deterioration of paint 
films, 96-98 

magnesium substrates in sea wa¬ 
ter, 96-97 

sea-water — calomel reference 
standard, 96 
special electrometer, 96 
steel substrates in sea water, 96 
surface potential as measure of 
corrosion resistance of a 
metal, 96-98 

Resistance, respiratory; see Respi¬ 
ratory resistance 

Respiration rates, instantaneous; 
effect of amount of work 
performed, 77-78 
effect of inspiratory resistance, 
78-79 

effect of strenuous exercise, 78, 
79 

effect of tropical environment, 78 
effect of weight of equipment 
carried, 78 
field studies, 82 
flow meter, 77 

inspiratory air flow determina¬ 
tions, 77-80 

maximum air-flow rates, 77-80 
minute volumes, 77-80 
Respiratory resistance, 80-83 

correlation between oxygen con¬ 
sumption and pulse rate, 82 
effect of training on subjects 
breathing through resist¬ 
ance, 82 



effect on oxygen deficit respira¬ 
tion rate, 82 

effect on respiration rates, 78-80 
maximum allowable under med- 
iurp and heavy work condi¬ 
tions, 80-83 

mean respiratory work rates, 81 
subjective reactions, 82 

Rifling pitch, effect on projectile 
stability, 68 

Rocket star, 21 

Rodents, damage to Quartermaster 
items, 149 

Roosenol 100 and 200 as tung oil 
substitutes, 164 

Rosin, effect on antifouling com¬ 
pounds, 99-100 

Rosin ester for gasoline sabotage, 
86 

RX, Tidewater Oil Company, for 
lubricating oil sabotage, 87 

Sabotage; of gasoline, 84-86 
of gasoline engines, 84-87 
of lubricating oil, 86-87 
proknock dispersal on enemy air 
fields to prevent take-off of 
planes, 85 

proknocks for addition to gaso¬ 
line, 84-85 

Safety devices; explosion protec¬ 
tion for aircraft fuel tanks, 
16-19 

fire retardant paint for Navy 
ships, 107 

oxygen masks, 49-52 

Saf-Te paint remover, 102 

Salicylanilide as leather disinfec¬ 
tant, 141 

Sand, chemically doped, for sinking 
oil spills in harbor waters, 
121 

Sand removal from aircraft engine 
air supply, 14-15 
channel air filter, 14 
cowling skimmer, 14-15 
dust skimmer, 14 

Sandblasting, wet, for paint re¬ 
moval from ships’ bottoms, 
103-104 

Santoresin for gasoline sabotage, 
86 

Saran-coated cellophane as pack¬ 
aging material, 173 

SDO as coatings for chemical 
munitions, 111 

Sea rescue work plane crash dye 
marker, 47-48 

Sea water; anaerobic corrosion of 
submersed metals, 104-107 



INDEX 


219 


anti-corrosion paints for ship 
bottoms, 92-109 

effect on water repellent fabrics, 
146 

Sea water purification for use as 
drinking water; chemical 
methods, 88-89 
double effect evaporation, 88 
electrolytic method, 88 
solar stills, 89-91 
vapor compression still, 91 
Sealing compounds for primers and 
fuzes, 113-115 

Seaming compounds, polyvinyl al¬ 
cohol, 111 

Select oil 200 as tung oil substitute, 
164 

Shearing stress; effect on viscosity 
of acryloid polymers, 5-6 
viscoelastic materials, 167 
Shell paramine hydrochloride for 
“doping” oil-sinking sand, 
121 

Shellac as sealing compound for 
delay element primers, 115 
Sherwin-Williams Kem-Tone; fire 
retardant properties, 109 
Shirlan as leather disinfectant, 141 
Shock absorbers, hydraulic fluids, 
1 

Shock wave flashes, research rec¬ 
ommendations for high in¬ 
tensity flash bombs, 26 
Shoes; adhesives, 139-140 
leather improvement, 141-142 
substitute shoe soles, 138-139 
Shrinkproofing of wool knitted 
items and fabrics, 176-177 
enzyme process, 177 
fundamental researches, 177 
halogenation processes, 177 
resin processes, 176-177 
solvent alkali process, 177 
test methods, 176 

Silicon oils; as base for hydraulic 
fluid, 3, 12 
inflammability, 12 
Ski pole shafts, bamboo, 153-155 
fabrication, 153 
performance tests, 153 
western hemisphere bamboo as 
substitute for Tonkin cane, 
153 

Skimmers for dust removal from 
air ducts; cowling skimmer, 
14-15 

dust skimmer, 14 

Sodium borohydride as source of 
hydrogen for meteorological 
balloons, 45-46 


advantages, 46 
production processes, 45-46 

Sodium hydride as source of hydro¬ 
gen for meteorological bal¬ 
loons, 41-45 

hydrogen generator for filling 
balloons, 43-45 

production by hydrogenation of 
sodium, 43 

use of sodium-aluminum mix¬ 
tures, 43-44 

Sodium silicate for treatment of 
soil for dust suppression, 
128-129 

Solar stills for production of drink¬ 
ing water from sea water, 
88-90 

anti-fogging coatings for trans¬ 
parent envelope, 90 
folded solar still for life raft use, 
90 

maximum efficiency, 90 
theory of operation, 89 

Soling materials for shoes, 139-140 

Solubility coefficient, water vapor 
permeability of plastic films, 

167 

Solubility of polyvinyl chloride res¬ 
ins, 170 

Solution properties of vinyl resins, 

168 

determination of polymer-liquid 
interaction by swelling mea¬ 
surements, 170 

Solvent-alkali shrinkproofing pro¬ 
cess, 177 

Solvents for paint removal, 102 

Southern Regional Laboratory 
treated fabric, flame retard¬ 
ant efficiency, 161 

Spectographic studies of photoflash 
bombs, 27-28 

Spencer-Kellogg experimental oil 
T-2 as tung oil substitute, 
164 

Spencer-Kellogg experimental oil 
XA-1 as tung oil substitute, 
164 

Sperry upper local turret, hydrau¬ 
lic fluid tests, 10 

Spinning projectiles; critical speed 
of liquid filled top, 66-67 
experiments with liquid filled top, 
66-68 

stability factor, 65-66 

Spirillum, sulfate-reducing bac¬ 
teria, 105 

Spodumene as source of lithium, 
42-43 



production of lithium hydroxide, 
43 

Sporovibrio desulfuricans, sulfate- 
reducing bacteria, 105 
Stability of thickened H under 
tropical storage conditions, 
59-61 

use of hexamethyline tetramine 
as a stabilizer, 59 
use of lined containers, 59 
Stability studies, spinning projec¬ 
tiles, 65-68; 4.2-in. chemical 
mortar shell, model studies, 
68 

liquid filled top experiments, 66- 
68 

stability factor, 65-66 
Standard Oil Development Com¬ 
pany, 12 

Star shells; see also Flares 

Navy standard star mixture, 21 
rocket star, 21-22 
Steam distillation, Levinstein H 
purification process, 55 
Steels, surface preparation for good 
paint adhesion, 94 
Stitch-tear test, leather substitutes, 
138 

Storage batteries, submarine, modi¬ 
fications for increased capa¬ 
city, 120 

Strain in viscoelastic materials, 167 
Stress and strain viscoelastic mate¬ 
rial, 167 

Submarine, peroxide driven, 132 
Submarine detection, underwater 
flare, 20 

Submarine storage battery, capa¬ 
city increase, 120 

Sulfate reducing bacteria; distribu¬ 
tion, 105 

effect in metal corrosion, 104-107 
Sulfur dichloride, use as proknock, 
85 

Sulfur monochloride, use as pro¬ 
knock, 85 

Sulfur trioxide, use as proknock, 
85 

Super Beckacite No. 1001 for gaso¬ 
line sabotage, 86 

Swelling measurements for deter¬ 
mination of polymer-solvent 
interaction, 170 

Synthetic rubbers; effect of hydrau¬ 
lic fluids, 8 
light aging, 171 

Tackiness of hydraulic fluids, 8 
Tanning agents, synthetic, 141-142 



220 


INDEX 


Temperature dependence of water 
vapor permeability, 167 
Temperature-viscosity characteris¬ 
tics of hydraulic fluids, 3, 8-9 
Tensile creep properties of plasti¬ 
cized vinyl films, 167-168 
effect of plasticizer composition, 
168 

effect of resin composition, 168 
experimental procedure, 168 
theoretical discussion, 168 
Tensile strength; leather substi¬ 
tutes, 138 
vinyl films, 172 

Teredos, damage to Quartermaster 
items, 149 

Tetrachlorophenol as leather dis¬ 
infectant, 141 

Textiles; flameproofing, 160-163 
wear resistance, 173-175 
Thermal oxidation, degradation of 
synthetic rubbers, 171 
Thickening agents for Levinstein H 
and other vesicant sprays, 
58-61 

asbestos fibers and ground news¬ 
paper, 58 
field trials, 57 

laboratory mortar tests, 57 
methyl methacrylate, 57-58 
preparation of thickened H, 58- 
59 

viscosity of thickened solutions, 
57 

Thin films; see Plastic films 
Thiodiglycol H mustard gas; pres¬ 
sure stability, 53 
stability under storage, 59-61 
Thixotropic gels formed by acrylic 
acid polymers at low temper¬ 
atures, 4 

3586 castor oil base hydraulic fluid, 
2 

3850 hydrocarbon base hydraulic 
fluid, 2, 10 

3GP12 hydraulic fluid, 7 
Thysanura, damage to Quartermas¬ 
ter items, 149 

Tidewater Oil Company, 87 
Tin, surface preparation for good 
paint adherence, 94 
Titanium, catalytic effect on speed 
of flash mixtures reaction, 24 
Titanium dioxide for pigmentation 
of chemical munitions lin¬ 
ings, 111 

Titanium tetrachloride, container 
coatings, 110 

Tonkin cane for ski pole shafts, 153- 
155 


Toxic materials for antifouling 
coatings, 97-102 
effect on bacteria, 107 
theories of fouling prevention, 
98-99 

Training, effect on performances of 
subjects breathing through 
respiratory resistance, 82 
Tretolite reagent L-28,097 for “dop¬ 
ing” oil-sinking sand, 121 
1,1,2-Trichloroethane, use as paint 
remover, 102 

Trichloroethylene, use as paint re¬ 
mover, 102 

Trichoptera, damage to Quarter¬ 
master items, 149 

Tricresyl phosphates; plasticizer 
for anticorrosive coating, 
114 

plasticizer for Vinylite VYNW, 
168 

Triethyl phosphate mixtures, low 
inflammability, 12 
Triethylamine, use in deleading of 
gasoline, 143 

Triethylene glycol for noninflam¬ 
mable hydraulic fluids, 12 
Trioctyl phosphate, plasticizer for 
Vinylite VYNW, 168 
Trioxane fuel unit for heating 
combat rations, 156, 157 
Troop feeding programs, 151-152 
Tung oil substitutes, 165-166 
29 inside white paint, 109 
Twill, wear resistance, 173 

Ultraviolet light, aging effect on 
polyvinyl chloride, 171 
Underwater coatings; see Coatings 
for Navy vessels 
Underwater flare, 20-21 
flare mixture, 21 
ignition systems, 23 
use of finely divided ingredients 
for complete combustion, 21 
United States Gypsum Company, 
128 

Uranine, use as plane crash dye 
marker, 47-48 

Urea as flameproofing agent, 163 
Urea-phosphate flameproofing, 162- 
163 

V-l flying bombs, 132 
Vacuum distillation process for 
Levinstein H purification, 
56 

Valves, inspiratory and expiratory 
in protective respiratory 
masks, 80-81 


airflow resistance determination, 
80 

Japanese army service mask, 80 
leakage determination, 80 
opening pressure determination, 
81 

Vapor compression still for distil¬ 
lation of drinking water 
from sea water, 91 
Varnishes, tung oil substitutes, 
165-166 

Vesicants; effect of drop size, 61- 
62 

effectivenes against troops, 61 
greater volatility of HP, 63 
Levinstein H mustard gas, 53-64 
linings and seaming compounds 
for containers, 110-112 
penetration of cloth, 62 
rate of evaporation, 61-62 
Sprayed from airplanes, 61-62 
tactical use, 60-62 
Virbio, sulfate-reducing bacteria, 
105 

Vickers drive unit, 10 
hydraulic fluid tests, 10 
Vickers piston, 6 
Vickers relief valve, 6 
Vinyl films; folding endurance, 
172 

tensile strength, 172 
viscoelastic properties, 167-168 
water vapor permeability, 167 
Vinyl polymers; degradation, 170 
relationship of mechanical prop¬ 
erties to molecular chain 
lengths, 172 

Vinyl resins; fractionation tech¬ 
niques, 169 
solubility, 170 

solution properties, 168-170 
Vinylite blast mats for dust sup¬ 
pression around artillery 
emplacements, 130 
Vinylite VMCH for anticorrosive 
fuze coating, 114 

Vinylite VYHH; as binder in anti¬ 
fouling compound, 101 
corrosion of resin-coated panels, 
95 

effect of plasticizer composition 
on creep characteristics, 168 
fire retardant properties, 109 
resistance to bacteria, 107 
Vinylite VYLF, molecular weight, 
169 

Vinylite VYNS, effect of plasticizer 
composition on creep charac¬ 
teristics, 168 



INDEX 


221 


Vinylite VYNW; effect of plasti¬ 
cizer composition on creep 
characteristics, 168 
effect of resin composition, 168 
intrinsic viscosity, 169 
molecular weight, 169 
Viscoelastic properties of plasti¬ 
cized vinyl films, 167-168 
experimental technique, 168 
theoretical stress and strain con¬ 
siderations, 167 
transition phenomena, 167 
Viscosity index of hydraulic fluids, 
9, 12 

centistoke viscosity of acryloid 
polymers, 4 
loss due to shear, 5-6 
requirements, 2-3 
temperature-viscosity character¬ 
istics, 4, 8-10 

Viscosity technique for molecular 
weight determination, 169 
Viscosity temperature require¬ 

ments of plastic dipping ma* 
terials for ration packaging, 
178, 179, 181 

Visual aids to submarine detection, 
underwater flare, 20-21 
Vulcanization, effect on oxidation 
rate of high polymers, 171 

Wakeless long-range peroxide- 

driven torpedoes, 132 
Water absorption test for leather 
substitutes, 138 

Water cans, interior finishes, 164, 
166 

Water emulsion paints, fire retard¬ 
ant properties, 109 


Water repellent finishes for fabrics, 
145-147 

absorption tests, 146 
drop-penetration test, 145, 149 
durability, 146 

effect of fabric construction, 146- 
147 

effect of laundering, 146 
effect of sea water immersion, 
146 

hydrostatic pressure tests, 146 
surface tests, 146 
water permeability test, 146 
Water vapor permeability of plas¬ 
tic films, 167, 180-181 
Waterproofing of plastic packag¬ 
ing; effect of handling, 178, 
180 

water-vapor transmission rates, 
178 

Water-soluble organic solvents for 
noninflammable hydraulic 
fluids, 12 

Wax impregnations for giving firm¬ 
ness to leather, 142 
Waxfree crude oils for use in hy¬ 
draulic fluids, 7 

Wear resistance of apparel textiles, 
173-175 

classes of damage, 173 
combat course results, 173, 175 
laboratory tests of abrasion re¬ 
sistance, 174-175 
test procedure, 173 
Western hemisphere bamboo as a 
substitute for oriental bam¬ 
boo, 153-155 


Westvaco shrinkproofing process, 
176 

Wet sandblasting method of paint 
removal, 103-104 
White flares, 21-23 
White ipaint No. 29; 109 
White phosphorous; container coat¬ 
ings, 110-112 
use as proknock, 85 
Wood-bottom ships, antifouling 
coatings, 102 

Wool shrinkproofing; see Shrink¬ 
proofing 

Wool waste as cork substitute for 
ordnance plugs, 119 
Work rates; effect on respiration 
rates, 77-79 

maximum allowable respiratory 
resistance for medium and 
heavy work, 80-83 
WP-1 wash primer, anticorrosive 
coatings, 101-102 

XA-1 for water can coating, 166 

Yellow CG dye, 38 
Yellow flares, 21-23 
Yellow GK dye, 38 

Zeo Karb H for removing salt from 
sea water, 88 

Zinc, surface preparation for paint 
adherence, 94 

Zirconium, catalytic effect on speed 
of flash mixture reaction, 24 
Zymol as tung oil substitute, 164 


DECL ASSIFIED 
By authority Secretary of 


SEP 2 i. 1960 

Defense rrvmo 'i A igust 1960 
LIBRARY OF CONGRESS 












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DECLASSIFIED. 

By authoritv Secretary of 

50 

Defense . i“st 1960 

LIBRARY u jNGRESS 





















